SERV1711-01 November 2005
GLOBAL SERVICE LEARNING TECHNICAL PRESENTATION
637G WHEEL TRACTOR-SCRAPER WITH C-9 ENGINE INTRODUCTION
Service Training Meeting Guide (STMG)
637G WHEEL TRACTOR-SCRAPER WITH C-9 ENGINE INTRODUCTION MEETING GUIDE 711
VISUALS AND SCRIPT AUDIENCE
Level II--Service personnel who understand the principles of machine systems operation, diagnostic equipment, and procedures for testing and adjusting.
CONTENT This presentation introduces the 637G Series of Wheel Tractor-Scrapers. This presentation covers machine arrangements, component locations, basic systems operation, hydraulic oil flow, air flow, and electrical current flow.
OBJECTIVES After learning the information in this presentation, the serviceman will be able to: 1. locate and identify the major components in the electrical, engine, power train, implement hydraulic, steering hydraulic, and air and brake systems; 2. explain the operation of the major components in the systems; and 3. trace the flow of oil, air, and electricity through the systems.
REFERENCES 637G Wheel Tractor-Scraper Service Manual 637G Operation and Maintenance Manual 637G Wheel Tractor-Scraper Specalog
RENR5710 SEBU7514 AEHQ5529
PREREQUISITES STMG 546 "Graphic Fluid Power Symbols" Estimated Time: 2 Hours Visuals: 150 Handouts: 24 Form: SERV1711-01 Date: 11/05 © 2005 Caterpillar Inc.
SERV1546
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TABLE OF CONTENTS INTRODUCTION ........................................................................................................................5 Machine Model Views............................................................................................................6 Machine Features....................................................................................................................7 OPERATOR'S STATION..............................................................................................................9 Caterpillar Monitoring System .............................................................................................19 Wheel Scraper Caterpillar Monitoring System ....................................................................28 ELECTRICAL SYSTEM ...........................................................................................................32 ENGINE......................................................................................................................................48 3408E Tractor Engine...........................................................................................................48 C-9 Scraper Engine...............................................................................................................57 POWER TRAIN .........................................................................................................................59 Tractor Power Train ..............................................................................................................60 Scraper Power Train .............................................................................................................73 IMPLEMENT HYDRAULIC SYSTEM....................................................................................82 Implement System Components ...........................................................................................86 Hydraulic System Operation.................................................................................................96 Cushion-Hitch Hydraulic System .......................................................................................104 Auger Hydraulic System.....................................................................................................108 637G Push-Pull Hydraulic System .....................................................................................112 STEERING HYDRAULIC SYSTEM......................................................................................116 Steering System Operation .................................................................................................122 AIR SYSTEM AND BRAKES ................................................................................................125 Air Charging Circuit ...........................................................................................................129 Air Brake Circuits...............................................................................................................135 Retarder Circuit...................................................................................................................141 Accessory Circuits ..............................................................................................................144 Air and Brake System Operation .......................................................................................146 TIER III G SERIES ..................................................................................................................150 Operator’s Station ...............................................................................................................150 Electrical System ................................................................................................................156 Engine .................................................................................................................................157 Implement System ..............................................................................................................169
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TABLE OF CONTENTS CONCLUSION.........................................................................................................................182 VISUAL LIST ..........................................................................................................................183 LAB HANDOUTS ...................................................................................................................186
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637G WHEEL TRACTOR-SCRAPERS WITH C-9 ENGINE INTRODUCTION
© 2005 Caterpillar Inc.
1
INTRODUCTION The 637G Wheel Tractor-Scrapers are a direct replacement for the 630E Series of Wheel Tractor-Scrapers. The 637G Wheel Tractor-Scrapers retain many of the proven features from the "E" Series machines and introduce additional performance and design improvements. This presentation discusses the systems, major components, and features of the 637G Wheel Tractor-Scrapers. The improvements to the 637G of Wheel Tractor-Scrapers include an updated operator station and display panel including the Caterpillar Monitoring System. The Implement Electronic Control System features a single electronic implement control lever. The transmission controller has been revised to simplify gear selection and provide operator defined top gear control. The tractor engine has been upgraded to the 3408E Hydraulic Electronically Controlled Unit Injection (HEUI) diesel engine with dual horsepower capability. The scraper engine has been upgraded to the C-9 HEUI diesel engine with dual horsepower capability.
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Machine Model Views The 631G Wheel Tractor-Scraper (top left view) is shown in the standard configuration with a bowl, ejector, and apron. The 631G can also be equipped with an auger (top right view). The 637G Wheel Tractor-Scraper is equipped with a rear engine in the scraper and also comes in a standard configuration (bottom left view) with a bowl, ejector, and apron. The 637G can also be equipped with an auger or a push-pull attachment (bottom right view) that includes a bail.
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MACHINE FEATURES - 3408E HEUI Diesel Engine - AMOCS Radiator - Implement Electronic System - Electronically Controlled Transmission - Updated Operator's Station - Caterpillar Monitoring System
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Machine Features 3408E HEUI Engine and C-9: The 3408E Hydraulic Electronic Control Unit Injection (HEUI) engine in the tractor and the C-9 HEUI engine in the scraper have dual horsepower operation and electronic control. Electronic control results in optimum engine/machine performance, simplified maintenance, and improved diagnostics. Advanced Modular Cooling System (AMOCS) Radiator: The modular design AMOCS radiator is less prone to plugging with a lower fin density. Serviceability is improved by allowing one module to be replaced rather than the entire radiator.
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Implement Electronic Control System: The implement system provides single lever implement control from the cab combining the traditional three implement levers into one. The joystick is used to control the bowl, apron, ejector, and auger. The bail up/down, transmission hold and cushion-hitch activation have also been incorporated into the joystick. The implement pilot system is electronically controlled which provides more precise control of the implements. Electronically Controlled Transmissions: The Transmission/Chassis Electronic Control Module (ECM) reduces power train stress by selecting the proper gear for any given engine rpm and ground speed, and by synchronizing engine and transmission speed while shifting. The tractor is equipped with a planetary power shift transmission with eight forward gears and one reverse gear. The operator can select and program the maximum top gear for precise machine control. The 637G Scrapers are equipped with a planetary power shift transmission with four forward speeds and one reverse speed. The scraper transmission is also electronically controlled. Updated Operator's Station: The operator's station includes an improved air suspension operator seat, standard air conditioning, and new switch console. Less frequently used switches have been moved to an overhead console. Caterpillar Monitoring System: The Caterpillar Monitoring System monitors the machine status and provides warning indications to the operator. Diagnostic codes are accessible through the main display module and through a laptop computer with Electronic Technician (ET) software.
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OPERATOR'S STATION The 637G operator's station provides styling, visibility, and comfort. The revised steering column has increased interior leg room and the less frequently used switches have been moved to the overhead console to improve visibility. A redesigned instrument panel includes the Caterpillar Monitoring System, indicator lights, and a switch to start the rear engine from the cab. The operator's seat is fully adjustable fore and aft and can swivel up to 30º in 10º increments. Armrests are provided on both sides of the seat. Standard air conditioning increases operator comfort and ventilation louvers have been relocated to improve airflow to the operator. Diagnostics can be performed from the operator's station using the service connector next to the operator's seat.
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4 1 5 1 4 2
2
3
3
7
6
5
The air suspension seat in the operator's station includes six adjustments. The top views show the following levers that control the air suspension seat position: -
Swivel release lever (1) Fore/aft lever (2) Up/down knob (3) Damping adjustment (4) Lumbar support lever (5)
The recline lever (6) is located on the right side of the seat below the seat cushion. The armrests can also be adjusted using the armrest adjustment knobs (7) located at the ends of the armrests.
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3
1 2
6
The steering column tilt/telescope control lever (1), located on the left side of the steering column below the steering wheel (2), is used to adjust the steering column tilt and height. Pull the tilt/telescope control lever up to tilt the steering column. Push the tilt/telescope control lever down to adjust the steering column height. The headlight dimmer/turn signal switch (3) is also located on the left side of the steering column.
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7
When the machine is equipped with the optional driveline retarder, the retarder control lever (arrow) is located on the right side of the steering column. The retarder (if equipped) provides continuous speed reduction during machine operation.
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2
1
3
8
The service brake pedal (1) is located on the floor of the cab. This view of the 637G shows two governor control pedals (2), one for the tractor and one for the scraper. Both pedals can be pressed with one foot. The governor control pedals are located to the right of the service brake pedal. Depress the governor control pedal to increase ground speed. Release the pedal to reduce ground speed. The differential lock switches (3) are also located on the cab floor. Both differential lock switches activate the electronic differential lock. The left switch is used with the seat facing forward and the right switch is used when the seat is turned to the right. Engaging the differential lock provides maximum traction. To engage the differential lock, push and hold the switch in the DOWN position. Release the switch to unlock the differential. The differential lock should not be engaged when the wheels are spinning.
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2
5
3
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1
4
9
The implement control lever (1) located on the right console provides a single control lever for the electronically controlled implement system. The transmission control lever (2) is used to select the desired machine direction and speed. The throttle lock control switch (3) engages the throttle lock to maintain the current engine speed. The parking brake control knob (4) is located between the implement control lever and the transmission control lever. To engage the parking brake, pull the knob up. Push the knob down to release the parking brake. The 637G Wheel Tractor-Scrapers equipped with an auger will have a scraper power limiter switch (5) located next to the throttle lock switch. The power limiter switch activates the scraper power limiter which reduces scraper engine power. The scraper power limiter is activated only when the auger is engaged.
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2
Text Reference
3
1
4
5
10
The overhead panel is located above the operator and includes the following toggle switches: - Heater/air conditioner switch (1) - Temperature control knob (2) - Fan speed switch (3) - Rear windshield wiper switch (4) - Bowl floodlight switch (5)
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1 2
3 4
5
11
The operator's station in the 637G Wheel Tractor-Scrapers includes a redesigned instrument panel and the Caterpillar Monitoring System. The Caterpillar Monitoring System panels (1) include (from left to right) the gauge cluster module, the main display module, and the speedometer/ tachometer module. The key start switch (2) is a three position key switch (OFF, ON, START). The switch must be in the OFF position to insert and remove the key. The scraper transmission neutral/run control switch (3) will engage and disengage the 637G scraper transmission. The Tractor-Scraper select switch (4), allows the operator to display information about the tractor or the scraper. The scraper engine start switch (5) is used to start the scraper engine from the tractor cab in the 637G models. Depress the switch to start the scraper engine. The key start switch must be in the ON position to start the rear engine.
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12
There are five indicators located at each end of the dash panel. The indicators on the left side of the dash are displayed in this view. The indicators (from top to bottom) are: Left turn indicator (1): Illuminates when the left turn signal is ON. High beam indicator (2): Illuminates when the tractor driving lights are on high beam. Apron float indicator (3): Illuminates when the apron float is engaged. Tractor indicator (4): Illuminates when the Caterpillar Monitoring System is in the Tractor Mode, indicating that the monitoring system is displaying tractor information. Scraper indicator (5): Illuminates when the Caterpillar Monitoring System is in the Scraper Mode, indicating that the monitoring system is displaying scraper information.
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1 2
3
4
13
The indicators located on the right side of the dash (from top to bottom) are: Right turn indicator (1): Illuminates when the right turn signal is ON. Transmission hold indicator (2): Illuminates when the transmission hold control is engaged. Ejector return indicator (3): Illuminates when the ejector is in the return Detent Mode and the ejector is moving to the return position. Throttle lock indicator (4): Illuminates when the throttle lock is engaged.
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CATERPILLAR MONITORING SYSTEM Gauge Cluster Module
Speedometer/ Tachometer Module
12
Mph Km/h
Main Display Module
° cKpa MilesKmRpm Liter Serv Code X10
3f
. . .
Action Alarm
Input Components
Display Data Link Scraper Transmission ECM (637G)
Tractor Engine ECM
Action Lamp
Scraper Engine ECM (637G)
Transmission / Chassis ECM
Cat Data Link
Input Components
Input Components
Input Components
Input Components
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Caterpillar Monitoring System The Caterpillar Monitoring System is a flexible, modular monitoring system that continuously monitors the wheel tractor-scraper systems. The Caterpillar Monitoring System components are: main display module, gauge cluster module, speedometer/tachometer module, an action lamp, an action alarm, various switches, and sensors. The "heart" of the system is the main display module where information is received, via the Cat Data Link, from switches, sensors, and the machine ECMs. The main display module processes the information, then activates various outputs. The Caterpillar Monitoring System includes three warning categories and provides visual and audible warning system outputs. The visual outputs include the alert indicators and the action lamp. The audible output is the action alarm.
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2
3 1 4
5 6
15
The Caterpillar Monitoring System components include a main display module (1), a speedometer/tachometer module (2), and a gauge cluster module (3). The main display module contains the processing functions for the system, a section that displays ten alert indicators (top half of module) and a bottom section that displays a digital readout. The alert indicator section uses inputs from switches, sensors, senders, and the CAT Data Link to alert the operator of machine conditions. The digital display area provides a six digit readout that shows machine operational hours, engine speed, distance, and diagnostic information. The speedometer/tachometer module displays the engine speed (gauge), the ground speed (left display), and the transmission actual gear, and direction (right display). The gauge cluster module displays four of the changing machine conditions that engineering determines are most often desired by the operator. The action lamp (4) flashes when a serious abnormal condition (Warning Category 2 or 3) exists. The action alarm (not visible) sounds in the event that a critical condition (Warning Category 3) exists.
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The mode select switch (5) allows the operator or technician to select from 10 different modes and 46 submodes of operation depending on machine model. Each mode or submode selects the functions to be displayed on the numeric readout window. The tractor-scraper select switch (6) which is found on 637G models only, allows the operator to display information about the tractor or the scraper.
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Quad Gauge
630G SERIES WHEEL TRACTOR-SCRAPER CATERPILLAR MONITORING SYSTEM
Speed / Tach.
Main Module 1
2
3
4
5
6
7
8
9
10
15 20
10
25
5
X100 30
0 C
Kpa
Miles
Km
Kph
Liter
MPH km/h
Serv Code
3F
X10
Display Data Link
Display Data Link
Tractor Transmission / Chassis ECM
Text Reference
Action Lamp Action Alarm Air Pressure Sensors
Cat Data Link
Secondary Steering Switch Fuel Level Sender Operator Mode Select Switch
Scraper Mode Select Indicator Tractor Mode Select Indicator
Tractor-scraper Select Switch Location Code Plug
Tractor Engine Control
Alternator "R" Terminal Service Port Connector (Cab)
Scraper Engine Control
Service Port Connector (Scraper) Converter Oil Temp Sensor
Scraper Transmission ECM
Fuel Differential Pressure Switch
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The Caterpillar Monitoring System main display module makes decisions based upon the inputs from the various switches, senders, and sensors installed on the system. The inputs tell the main display module how to operate and the status of the machine systems. The outputs associated with the monitoring system are used to notify the operator of both normal and abnormal machine conditions The output components include: the main display module, the scraper display module, the action lamp, and the action alarm. NOTE: The main display module also provides power supply outputs (+8 VDC) to the PWM sensors connected to the module, (+9 VDC) to the gauge cluster, and speedometer/tachometer modules.
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2 1 4 3
17
The gauge cluster module is located on the top left side of the dash panel. The gauge cluster module gauges and their associated warning(s) are: Coolant temperature gauge (1): Indicates engine coolant temperature. Warning Category 2. Torque converter oil temperature gauge (2): Indicates torque converter oil temperature. Warning Category 2. Air supply pressure gauge (3): Indicates air pressure in the air tanks. Warning Category 2. Fuel level gauge (4): Indicates fuel level. Warning Category 1.
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1
2
3
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The speedometer/tachometer module is located on the top right side of the dash and includes the following components: Analog tachometer (1): Displays the tractor engine rpm during machine operation. When the tractor-scraper select switch is activated, the tachometer displays the scraper rpm. Digital speedometer (2): Displays the machine ground speed. The speedometer is set to a default reading in miles per hour (mph), but can display the optional reading in kilometers per hour (km/h). Active gear and direction readout (3): Displays the direction of travel during machine operation. The readout also displays the transmission gear. When the tractor-scraper select switch is activated the scraper transmission gear is displayed.
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2
7
3
8
4
9
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5
6
10
11
1
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The digital display window (1) shows data for several machine systems. The default reading on the 637G display window is the scraper engine tachometer. Other information that can be displayed includes: the hourmeter, odometer, tachometer, diagnostic scrolling, top gear, and hydraulic oil temperature. The alert indicators and their associated warning(s) are: Engine coolant flow (2): Indicates no coolant flow to the engine. Warning Category 3. Air pressure (3): Indicates low air pressure in the air system or air system failure. Warning Category 1 and 3. Engine oil pressure (4): Indicates low engine oil pressure. Warning Category 3. Secondary steering (5): Indicates that the secondary steering system is engaged. When the secondary steering system is engaged, the primary steering system has failed. Warning Category 3. Engine coolant temperature (6): Indicates tractor engine coolant temperature is too high. Warning Category 2. Torque converter oil temperature (7): Indicates torque converter oil temperature for the tractor is too high. Warning Category 2. Park brake (8): Indicates parking brake is engaged. Warning Category 1, 2, and 3.
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Charging system (9): Indicates the alternator for the tractor engine is malfunctioning. Warning Category 1 and 2. Power train system (10): Indicates a problem with the engine control system or the transmission control system. Warning Category 1, 2, and 3. Hydraulic system failure (11): Indicates the hydraulic oil temperature is too high or a problem has occurred in the implement hydraulic system. Warning Category 1, 2, and 3.
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1
2
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3 4
5
6
8 7
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The panel light switch (1) is used to turn the scraper panel lights on and off. The scraper engine start switch (2) is used to start the scraper engine. Push the switch up to start the scraper engine. The tractor key start switch (not shown) must be in the ON position to start the scraper engine. The action lamp (3) flashes when a serious abnormal condition (Warning 2 or 3) exists. The air inlet heater lamp (4) luminates when the air inlet heater is activated. The engine speed control switch (5) is used to set the speed of the scraper engine. The engine ON/OFF switch (6) controls the electrical power to the scraper engine ECM. If the switch is in the OFF position, the scraper engine can not be started from the cab or the scraper control panel. The engine shutdown switch (7) is used to turn the scraper engine off. Raise the cover and push the switch up to shut the scraper engine off. The diagnostic connector (8) allows the Electronic Technician service tool (not shown) to be connected to the machine electrical system.
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Text Reference
637G SCRAPER CATERPILLAR MONITORING SYSTEM 1
3
6
8 °c
Kpa
Miles
5 9 Km
Kph
Display Module (Cab)
Liter Serv Code X10
Cat Data Link
Action Lamp
Engine Oil Pressure Switch
Alternator "R" Terminal Engine Coolant Temperature Sender
Diagnostic Connector
Converter Oil Temperature Sender
Harness Code Plug
21 Wheel Scraper Caterpillar Monitoring System The Caterpillar Monitoring System monitors inputs and outputs from the wheel scraper. The wheel scraper system does not include a gauge cluster or a speedometer/tachometer module. The information from the wheel scraper can be displayed in the cab by toggling the tractorscraper switch on the dash of the cab. The 637G Wheel Scraper Caterpillar Monitoring System input components include: - Scraper engine oil pressure switch - Scraper engine coolant temperature sender - Scraper torque converter oil temperature sensor - Scraper engine coolant flow switch - "R" terminal on the scraper alternator - Harness code plug The 637G Wheel Scraper Caterpillar Monitoring System output components include: - Four alert indicators and display window on the tractor display module - Action lamp - Action alarm (cab)
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2
1
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3
4
5 6
7
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The tractor display window (7) shows data for the wheel scraper by pushing the tractor-scraper select switch. The alert indicators and their associated warning(s) are listed: Engine coolant flow (1): Indicates no coolant flow to the tractor engine. Warning Category 3. Engine oil pressure (2): Indicates low engine oil pressure. Warning Category 3. Engine coolant temperature (3): Indicates scraper engine coolant temperature is too high. Warning Category 2. Torque converter oil temperature (4): Indicates torque converter oil temperature for the scraper is too high. Warning Category 2. Charging system (5): Indicates the alternator for the scraper engine is malfunctioning. Warning Category 2. Power train system (6): Indicates a problem with the transmission control system. Warning Category 1.
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1
2
23
The diagnostic connector (1) is located on the electrical center (2) to the left of the operator's seat. The diagnostic connector allows the Communications Adapter II service tool or the ET service tool (not shown) to be connected to the machine electrical system.
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The service connector (arrow) is located below the implement control lever behind a panel. The service connector provides a connection point for the 4C-8195 Control Service Tool (not shown). The 4C-8195 Control Service Tool provides the interface which allows diagnostic codes to be displayed on the Caterpillar Monitoring System main display panel.
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Text Reference
630G SERIES WHEEL TRACTOR-SCRAPERS ELECTRONIC CONTROL SYSTEM Tractor Engine ECM
Scraper Engine ECM (637G)
Tractor Main Display Module
Scraper Transmission ECM
1
2
3
4
5
6
7
8
9
10
C
Kpa
Miles
Km
Kph
Transmission / Chassis ECM
Liter Serv Code X10
Cat Data Link Tractor Engine
Scraper Engine
Scraper Trans.
Tractor Engine Status/ Faults
Fuel Rail Pressure
Fuel Rail Pressure
Braking System
Tractor Trans Faults
Tractor Engine Derate
Scraper Engine Derate
Scraper Engine Derate
Scraper Engine Faults Scraper Trans. Faults
Service Port Connector (Operator Station)
Scraper Monitor Sys. Faults
Service Port Connector (Scraper)
Bowl Control
Tractor Trans.
Ejector Control
Braking System
Apron Control
Tractor Engine Overspeed
Cushion Hitch Control Bail or Auger Control
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ELECTRICAL SYSTEM The 637G Wheel Tractor-Scrapers electronic control system modules communicate across the CAT Data Link. This view shows the relationship between the electronic control systems and the machine subsystems they operate on the 637G Wheel Tractor-Scrapers. The 637G Wheel Tractor-Scraper has five electronic control systems. The five electronic control systems and the vehicle subsystems they control are: 1. Tractor Engine ECM which controls the wheel tractor 3408E engine: - Injection system - Fuel rail pressure - Derating
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2. Tractor Transmission/Chassis Electronic Control Module (ECM): - Bowl control - Ejector control - Apron control - Cushion-hitch control - Bail or auger control - Tractor transmission - Air system - Tractor engine overspeed 3. Scraper Transmission Electronic Control Module (ECM): - Scraper transmission - Scraper engine derating 4. Tractor Caterpillar Monitoring System Main Display Module: - Tractor engine status and faults - Tractor transmission status and faults - Scraper engine status and faults - Scraper transmission status and faults - Scraper monitoring system faults 5. Scraper Engine ECM controls the C-9 (637G only): - Injection system - Fuel rail pressure - Derating The five electronic control systems are all connected through the CAT Data Link. Information is shared between each electronic control module to perform functions within each individual control system. INSTRUCTOR NOTE: For detailed information on 630G Series Electronic Control System functions refer to the appropriate Electronic Control System Service Manual module.
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1 2
3
4
26
The Tractor Engine ECM (1) is located on the top right side of the engine. The Tractor Transmission/Chassis ECM (2) is mounted below the cab on the left side of the machine. The Scraper Engine ECM (3) is located on the right side of the engine. The Scraper Transmission ECM (4) is located behind the fuel tank at the rear of the scraper bowl above the scraper transmission.
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1 2
3
4 6
5
27
The electrical center (1) is located at the left side of the operator's seat. The machine fuses (6) are located inside the electrical center. Circuit breakers located on the front of the electrical center are: - Key switch circuit (2) - Headlamp circuit (3) - Stop/tail/turn circuit (4) - Blower motor circuit (5)
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Text Reference
630G SERIES WHEEL TRACTOR POWER DISTRIBUTION
Electrical System Analyzer Connector
Stop / Tail / Turn Breaker Alternator
ALT R
+
+
+
Bus Bar
Alternator Breaker
Main Relay
Bus Bar
-
Battery (4)
+ +
-
Key Start Switch Bus Bar
Blower Motor Breaker
Wipers, Spare, Bowl Flood, Side Flood
Engine ECM Breaker
Air Dryer, Differential Lock, Cigar Lighter, Fuel Pump
Key Start Switch Breaker
Monitoring Sys, Start Aid, Seat, Spare
Running Lamp Breaker
Disconnect Switch
Converter, Transmission ECM, Spare, Spare
Implement ECM, Horn, Spare, Spare
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This diagram shows the 637G Wheel Tractor power distribution subsystem. A 24 Volt electrical system is used on the 637G Wheel Tractor. Power comes from the alternator and batteries to provide electrical energy to the on-board electrical systems. The main relay isolates components that should not be energized with the key start switch in the OFF position, which helps to prevent the batteries from discharging. Discharged batteries will cause difficulties in starting the machine due to low battery voltage.
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637G WHEEL SCRAPER POWER DISTRIBUTION AND CHARGING SUBSYSTEM
Scraper Load Resistor
Text Reference
Key Start Switch
Tractor Operator Station
Key Start Switch Breaker
Batt +
Main Relay Scraper Main Power Breaker Scraper Engine Control Breaker
Scraper Start Switch Breaker
Alternator Breaker Alternator
Engine ECM
Scraper Jump Start Receptacle
Scraper Starter Motor
Disconnect Switch
Battery (2)
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This illustration shows the Scraper Power Distribution and Charging Subsystem on the 637G Wheel Tractor-Scraper. The 637G Wheel Tractor-Scraper uses power from the alternator to charge the batteries for starting the engine and to power the scraper engine shutdown system. The scraper engine has a 24 Volt electrical system. During normal machine operation, current from the alternator passes through the alternator breaker to charge the batteries and power the engine shutdown control. The engine shutdown control is powered even with the tractor key start switch and scraper engine off. A load resistor is used to maintain a minimal electrical load on the alternator to keep the alternator powered. Power at the alternator helps avoid false low voltage warnings from the Caterpillar Monitoring System when the batteries are fully charged.
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Text Reference
All other electrical devices on the scraper are powered by the tractor electrical system. A scraper main relay is used to isolate the tractor electrical system from the scraper electrical system. The scraper main relay is also used as part of the scraper engine shutdown system. The Scraper Power Distribution and Charging Subsystem also includes an auxiliary jump start receptacle, which allows the engine to be jump started electrically without direct access to the engine compartment.
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Text Reference
630G SERIES WHEEL TRACTOR STARTING / CHARGING / SHUTDOWN CIRCUIT Start Aid Relay Start Aid Solenoid
Cat Monitoring System 1
2
3
4
5
6
7
8
9
10
C
kPa Miles km
Engine ECM
Ground Level Shutdown Switch
kph Liter Serv Code X10
Start Aid Input
ADEM Breaker
Start Relay
Alternator Breaker Alternator
Transmission / Chassis ECM
CDL
Key Start Switch Key Start Switch Breaker
Main Breaker Bus Bar Jump Start Receptacle
Battery (4) Disconnect Switch
Start Motor
30 The Starting/Charging Shutdown Subsystem for the 637G Wheel Tractor engine is shown in this diagram. This subsystem is made up of the following standard components: 1. Ground level shutdown switch 2. Start relay 3. Alternator "R" terminal 4. Alternator breaker 5. Key start switch 6. Key start switch breaker 7. Jump start receptacle 8. Bus bar 9. Starter motor 10. Batteries (quantity 4) 11. Disconnect switch 12. Main breaker
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Text Reference
This subsystem can also be equipped with the following attachment components: 1. Ether start aid solenoid 2. Start aid relay The Engine ECM, Transmission/Chassis ECM, and Caterpillar Monitoring System main module perform functions necessary for starting the wheel tractor engine. The starting procedure (starting logic) is discussed on the following page. This subsystem has three functions: 1. Starting and shutting off the 637G 3408E engine 2. Charge the machine batteries 3. Provide power to the on-board electrical and electronic equipment. During normal machine operation, current from the alternator passes through the alternator breaker to charge the batteries and power the machine's equipment. The subsystem also includes an auxiliary jump start receptacle, allowing the machine to be electrically jump started without direct access to the tractor engine compartment.
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Text Reference
630G SERIES WHEEL TRACTOR STARTING LOGIC Actual Gear Module and Transmission Selector Switch in Neutral?
Begin
Key Start Switch To "Start" Position
Transmission / Chassis ECM
Yes
No
Start Engine Transmission / Chassis ECM
Engine ECM
Ether Aid Start Logic Done
Neutralize All Implements
Engine ECM
31
This decision diagram shows the starting logic for the 3408E diesel engine used on the 637G Wheel Tractors. The Transmission/Chassis ECM and Engine ECM are involved in the starting procedure. The starting procedure begins when the key start switch is turned to the START position. The Transmission/Chassis ECM checks to see the position of the transmission selector switch and the actual gear module. If the Transmission/Chassis ECM receives a signal from either one of these switches that it is not in the NEUTRAL position, the starting procedure is stopped. If inputs from the selector switch and the actual gear module show that the transmission is in the NEUTRAL position, the starting procedure continues. The Transmission/Chassis ECM DE-ENERGIZES all implement functions. The Transmission/Chassis ECM issues a start command to the Engine ECM. The Engine ECM performs the ether start aid logic, if the machine is equipped with the ether starting aid option. The Engine ECM ENERGIZES the start relay and the starter motor and the engine starts.
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Text Reference
When the engine has started, the Transmission/Chassis ECM energizes the implement functions.
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Text Reference
637G WHEEL SCRAPER ENGINE STARTING LOGIC Scraper Start Key to "Start" Position
Tractor Actual and Selected Transmission in Neutral and Scraper Engine not Running?
Tractor Begin
Cab Key Start Switch To "On" Position Scraper
Scraper Transmission ECM
Yes
No
Start Engine Done
Scraper Transmission ECM
32
This decision diagram shows the starting logic for the scraper engine used on the 630G Series Wheel Scrapers. The scraper Transmission ECM, scraper Engine ECM, and Transmission/Chassis ECM are involved in the starting procedure. The starting procedure begins when the key start switch is turned to the START position. The scraper Transmission ECM checks to see the position of the transmission selector switch, the actual gear module, and that the scraper engine is not running. If the Transmission ECM receives a signal from either one of these switches that it is not in the NEUTRAL position or that the scraper engine is running, the starting procedure is stopped. If inputs from the selector switch and the actual gear module show that the scraper transmission is in the NEUTRAL position, the starting procedure continues. The scraper Transmission ECM sends an output signal to the Transmission/Chassis ECM to DE-ENERGIZE all implement functions.
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Text Reference
The Transmission/Chassis ECM DE-ENERGIZES all implement functions and sends a confirmation output back to the scraper Transmission ECM. The scraper Transmission ECM ENERGIZES the start relay and the starter motor and the engine starts. When the engine has started, the Scraper Transmission ECM sends a signal to the Transmission/Chassis ECM to energize the implement functions. The Transmission/Chassis ECM sends a confirmation signal back to the scraper Transmission ECM when the implement functions have been reactivated.
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Text Reference
2
1
3 4
33
The tractor batteries (1) are located under a cover on the right side of the tractor frame. The tractor battery disconnect switch (2) is located on the right side of the tractor behind the tractor engine access panel. Turn the key counterclockwise to the OFF position to deactivate the tractor electrical system. Turn the key start switch clockwise to the ON position to active the tractor electrical system. The scraper batteries (3) are located on the left side of the scraper above the left rear wheel. The scraper battery disconnect switch (4) is located on the right side of the scraper engine. Turn the key counterclockwise to the OFF position to deactivate the scraper electrical system. Turn the key start switch clockwise to the ON position to active the scraper electrical system.
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Text Reference
2 1
4
3
34
The tractor engine shutdown switch (1) is located on the left side near the front of the tractor and is used to shut the tractor engine OFF from the ground. The scraper engine shutdown switch (2) is located at the rear of the scraper on the right side and is used to shut OFF the scraper engine from the ground. The tractor auxiliary start receptacle (3) is located on the right side of the tractor behind the engine access panel. The scraper auxiliary start receptacle (4) is located at the rear of the machine. The auxiliary starting receptacles are used to jump start the engines using another machine or an auxiliary power pack.
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Text Reference
1
2
35
The 637G Wheel Tractor-Scraper electrical system is designed in a modular concept to provide maximum machine serviceability. The machine wiring harness contains several disconnect points at various locations throughout the machine. The graphic in the top right view shows the general design of the modular wiring harness system on the 637G Wheel Tractor-Scraper. The tractor engine wiring disconnect (1) is shown in the bottom left view and the scraper engine wiring disconnect (2) is shown in the bottom right view. A connector is provided where a harness or cable passes from one machine section or major component to another. This allows each section of the machine to be electrically disconnected from an adjacent section without cutting wires. All electrical connectors are clearly marked with the correct connector already installed. This modular design minimizes the amount of time and effort needed to disconnect and reconnect machine components.
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Text Reference
2 3
4
1
5
6
36
ENGINE 3408E Tractor Engine The 637G Tractor uses the 3408E HEUI Diesel Engine with a dual horsepower rating of 450/490 HP at a rated speed of 2000 rpm. The dual horsepower rating limits the engine output when the transmission is in first and second gears unless the operator has the optional auger engaged. Increased horsepower is available when the auger is engaged and when the tractor is operating in the higher transmission gears. The engine fuel system and engine operation is controlled by an Engine Electronic Control Module (ECM). A hydraulic pump mounted in the vee of the engine supplies the actuating pressure for the injectors. The air cleaner housing (1), radiator sight glass (2), engine oil filler cap (3), engine oil dipstick (4), engine oil filters (5), and engine oil S•O•S tap (6) are visible in this view.
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Text Reference
1 2
3
4 5
37
The primary fuel filter/water separator (3), secondary fuel filter (5), and electric fuel priming pump (1) are located in front of the hydraulic tank on the right side of the machine. Also visible in this view are the fuel priming pump switch (2) and the fuel differential pressure switch (4).
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Text Reference
1 2
6 5
4 3
38
The following components are visible on the right side of the engine: - Engine filler tube (1) - Engine oil dipstick (2) - Engine oil filters (3) - Transmission oil cooler (4) - ECM (5) - Air compressor (6)
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5 4
2
1 3
39
The following components are visible on the left side of the engine: - Alternator (1) - Air conditioning compressor (2) - Starter (3) - Air breather (4) - Turbocharger (5)
Text Reference
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Text Reference
3 1
2
40
This rear view of the 3408E engine shows the retarder (1), retarder control valve (2), and the air compressor (3).
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Text Reference
3408E / 3412E HEUI FUEL SYSTEM To Lube System Heui
Hydraulic Temperature Sensor Cold Start Oil Reservoir
Oil Filter
Hydraulic Supply Pump Group
Oil Cooler Lube Oil Pump
Fluid Manifold Hydraulic Passage
Oil Pressure Sensor
Fuel Hydraulic Temperature Pressure Sensor Sensor Fluid Manifold Hydraulic Passage
Cool Down Circuit
Pump Control Valve Fuel Transfer Pump
HEUI
ECM
Secondary Fuel Filter
Primary Fuel Filter Water Separator Oil Sump
Pressure Regulating Valve
Fuel Tank
41
The electronic components in the HEUI fuel system are very similar to those used in other EUI systems. However, in the HEUI system, the injectors are not actuated by a camshaft. A high pressure hydraulic pump, which draws oil from the pressure side of the lubrication pump, raises the pressure to a maximum of 22800 kPa (3300 psi). The pressure is controlled by the Tractor Engine ECM. The hydraulic flow is directed to hydraulic actuators in each injector. The injectors are electronically signalled (as in the EUI system) to permit oil under high pressure to move a piston which then moves the fuel plunger.
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Text Reference
2
1
42
The principal component in the HEUI system, the Tractor Engine ECM (1), is mounted on top of the right front valve cover. The ECM is the "heart" of the engine. The ECM performs engine governing, timing, and fuel limiting. It also reads sensors and communicates to the Caterpillar Monitoring System through the CAT Data Link. The hydraulic supply pump group (2) is mounted in the vee of the engine. Flow from this pump supplies the actuating pressure for the injectors. The fuel transfer pump (not visible) is mounted on the rear of the hydraulic pump.
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Text Reference
43
The 3400 HEUI unit injector is electrically similar to the 3500 electronic unit injector. The injector is controlled electrically by the Tractor Engine ECM but is actuated hydraulically. The signal from the ECM controls the opening and closing of the solenoid valve. The solenoid valve controls the flow of high pressure hydraulic oil to the injector. This system enables the ECM to control fuel volume, timing, and injection actuation pressure (hydraulic supply pump pressure).
WARNING
The injector solenoids operate on 105 Volts direct current. Always remain clear of the injector area when the engine is running or electric shock may occur.
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Text Reference
630G WHEEL TRACTOR-SCRAPER TRACTOR ENGINE CONTROL Cat Data Link
Fuel Injectors (8)
Ground Level Shutdown Switch Throttle Lock / Back-up Switch
Coolant Temp. Sensor Fuel Temp. Sensor
Start Aid Switch
Intake Air Temp. Sensor
1 6
2
3
4
5
7
8
9
0
15 10
Kpa Miles
Km Kph Liter Serv Code X10
20 25
5 0
C
Atmospheric Press. Sensor
X100 30 Mph Km/h
3f
Caterpillar Monitoring System Key Start Switch
Turbo Inlet Pressure Sensor Turbo Outlet Press. Sensor
Throttle Sensor
Engine Oil Press. Sensor Throttle Lock Lamp
Coolant Flow Switch Timing Calibration Probe
Ether Starter Relay
Primary Speed / Timing Secondary Speed / Timing Pump Control Solenoid Hydraulic Oil Pressure Sensor Engine Oil Temp. Sensor
44
The Tractor Engine ECM communicates with the 637G machine modules over the CAT Data Link. The ECM receives inputs from various sensors and switches. The ECM processes the signals and sends corresponding output signals to the fuel injectors, HEUI pump control valve solenoid, Caterpillar Monitoring System, and other output components over the Cat Data Link. INSTRUCTOR NOTE: For more information on the 3408E engine, refer to the Service Training Meeting Guide "3408E/3412E Engine Controls--Hydraulic Electronic Unit Injection (HEUI)" (Form SERV1672).
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Text Reference
1 2 3 4
6
5
7 9
8
45
C-9 Scraper Engine The following components are located on the right side of the C-9 Scraper Engine (machine right side): - Fuel priming switch (1) - Fuel priming pump (2) - Engine oil change quick coupler (3) - Engine oil dipstick (4) - Engine oil fill cap (5) - Primary fuel filter (6) - Fuel shutoff valve (7) - Secondary fuel filter (8) - Scraper transmission oil filter housing (9)
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Text Reference
1
2
4
3
46
The following components are located on the right side of the C-9 Scraper Engine (machine left side): - Coolant sample port (1) - Engine oil sample port (2) - Transmission oil cooler (3) - Engine oil filter (4)
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Text Reference
WHEEL TRACTOR-SCRAPER POWER TRAIN COMPONENTS
47
POWER TRAIN This view shows the major power train component locations on the 637G machines. The colors used to identify the various components are: Yellow
- Engine
Red
- Transmission
Blue
- Drive shaft
Brown
- Final drive
The 637G Wheel Tractor-Scrapers use an electronically controlled power shift transmission in the tractor and scraper. The tractor transmission provides one reverse and eight forward gears. The scraper transmission provides one reverse and four forward gears.
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Text Reference
WHEEL TRACTOR-SCRAPER TRACTOR POWER TRAIN COMPONENTS
Transfer Gears
Drive Shaft
Retarder
Torque Converter Transmission
Final Drive Pinon Gear
Diesel Engine
Differential
48
Tractor Power Train This view shows the major tractor power train component locations. The tractor transmission provides eight forward speeds and one reverse speed. The transmission is controlled by the Transmission/Chassis ECM and the transmission hydraulic system. Power from the tractor engine flows to the optional retarder (if equipped), to the transmission drive shaft transfer gears and to the torque converter. Power from the torque converter flows to the individual clutch modulated (ICM) power shift transmission. Power from the transmission flows through the pinon gear to the differential. Power from the differential flows through the axles and final drives to the wheels.
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Text Reference
49
Operation of the 637G Tractor transmission is controlled by the Transmission/Chassis ECM (arrow). The Transmission/Chassis ECM is located below the cab on the left side of the tractor. A panel has been removed in this view. The Transmission/Chassis ECM electronically controls the shifting of the tractor ICM transmission based on the programming stored in the ECM memory. The ECM continuously monitors machine conditions and operator inputs required to control the transmission. The ECM also receives information from other electronic machine control systems over the Cat Data Link. The Transmission/Chassis ECM compares the input information to its stored memory information and then decides when to shift the transmission.
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Text Reference
630G SERIES WHEEL TRACTOR TRANSMISSION / CHASSIS ELECTRONIC CONTROL SYSTEM
Input Components
Output Components
ECM Location Code
Cat Data Link
Electronic Service Tool
Shift Lever Position Sensor
Tractor Engine ECM
Transmission Gear Position Sensor
Scraper Engine ECM
Engine Output Speed Sensor
Scraper Transmission ECM
Transmission Output Speed Sensor Key Start Switch
°c
Kpa
Miles
Km Rpm Liter
.. .
Caterpillar Monitoring System
Serv Code X10
Tractor Transmission Neutral / Run Switch
Upshift Solenoid Downshift Solenoid
Parking Brake Switch Starter Relay
Pilot Supply Pressure Sensor Retarder Pressure Switch
Tractor Parking Brake Solenoid
Tractor Air Pressure Sensor Tractor Service Brake Pressure Switch
Scraper Parking Brake Solenoid
Tractor Parking Brake Pressure Switch Scraper Air Pressure Sensor
Brake Air Supply Solenoid
Scraper Service Brake Pressure Switch Scraper Parking Brake Pressure Switch
Back-up Alarm
50
The various inputs and outputs to the tractor Transmission/Chassis ECM that control power train functions are shown in this view. Components and sensors providing input to the Transmission/Chassis ECM include: -
ECM location code plug Shift lever position sensor Transmission gear position sensor Engine output speed sensor Transmission output speed sensor Key start switch Tractor transmission neutral/run switch Parking brake switch Pilot supply pressure sensor Retarder pressure switch Tractor air pressure sensor Tractor service brake pressure switch Tractor parking brake pressure switch
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Text Reference
- Scraper air pressure sensor - Scraper service brake pressure switch - Scraper parking brake pressure switch Outputs from the Tractor Transmission/Chassis ECM go to the following components and indicators: -
Tractor Engine ECM Scraper Engine ECM Scraper Transmission ECM Caterpillar Monitoring System Upshift solenoid Downshift solenoid Starter relay Tractor parking brake solenoid Scraper parking brake solenoid Brake air supply solenoid Back-up alarm
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Text Reference
4 2
1
3
51
This view shows the tractor transmission (1) which is located at the rear of the 637G tractor. The transfer gear case (2), torque converter housing (3), and implement/steering pump (4) are also visible in this view. The transmission operates in converter drive during REVERSE, FIRST, and SECOND speeds and operates in direct drive during THIRD through EIGHT speeds. The transmission has five stationary clutches, three planetary units, and two rotating clutches. Clutches 2 and 4 are the rotating clutches. The transmission is divided into an input section and an output section. The input section consists of clutches 1, 2, and 3 which are the directional clutches. The output section consists of clutches 4, 5, 6, and 7 which are the speed clutches. INSTRUCTOR NOTE: Refer to the "631G Wheel Tractor Power Train System Operation, Testing and Adjusting" Service Manual (Form RENR5709) and the "637G Wheel Tractor Power Train System Operation, Testing and Adjusting" Service Manual (Form RENR5709) for diagrams of the transmission.
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Text Reference
630G SERIES WHEEL TRACTOR TRANSMISSION CLUTCH ENGAGEMENT CHART Transmission Speed
Engaged Clutches
Reverse
1 and 7
Neutral
4
First Speed
1 and 6
Second Speed
1 and 5
Third Speed
3 and 6
Fourth Speed
2 and 6
Fifth Speed
3 and 5
Sixth Speed
2 and 5
Seventh Speed
3 and 4
Eight Speed
2 and 4
52
This chart shows the clutches that are engaged in each gear range for the 637G Wheel Tractor transmission. The No. 4 clutch is engaged in NEUTRAL while the No. 7 clutch is used only during operation in REVERSE. The No. 1 clutch is used only during operations in REVERSE, FIRST, and SECOND speeds. REVERSE, FIRST, and SECOND speeds are converter drive ranges. The one-way lockup clutch is engaged to provide direct drive operation for all the higher gear ranges (THIRD through SEVENTH). Clutches 1, 2, and 3 are the transmission input clutches. Clutch No. 1 is used in torque converter drive while clutches 2 and 3 are used in direct drive. The output section of the transmission include clutches 4, 5, 6, and 7. Clutch No. 7 provides reverse speed.
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Text Reference
2
1 3
53
The transmission control lever (1) is located on the right console in the cab and is used to select the desired machine direction and speed. The transmission control lever has five positions: REVERSE, NEUTRAL, FIRST, SECOND, and DRIVE. The transmission control lever lock button (2) must be pressed to mechanically unlock the lever before it can be moved. When the transmission control lever is in the DRIVE position the transmission will automatically shift between SECOND and any higher speed that is selected. The top gear select button (3) is used to select the desired top speed. With the engine running and the transmission control lever in the DRIVE position, pressing and holding the top gear select button will cycle the gear indicator through the available gears. When the top gear select button is released the top drive gear is set. The monitoring system will show the gear position on the display panel. NOTE: The machine is equipped with an engine neutral start system. The engine will not start unless the lever is in the NEUTRAL position.
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Text Reference
630G SERIES WHEEL TRACTOR TRANSMISSION HYDRAULIC SYSTEM Downshift And Upshift Solenoids
Priority Valve
Selector Group
T/C Inlet Valve
Scavenge Pump
Pressure Control Group
Flywheel Case
Drive Shaft Bearing
Oil Filter Transmission Case
Charge And Scavenge Pumps
Drive Shaft
Diff Case
Retarder Control Valve
Lube Line Retarder Scavenge Screen
Magnetic Screen
Scavenge Screen
Transfer Gear Case
T/C
Cooler Return Line
Oil Cooler
Retarder Air Valve
54
This diagram shows the flow of oil through the tractor power train hydraulic system components. Oil is drawn from the bevel gear case through the magnetic screen to the transmission charging pump. Oil flows from the transmission charging pump through a filter to the to the upshift and downshift solenoids, the priority valve, and selector valve group. Oil flows from the selector valve group to the pressure control group for transmission clutch engagement and to the torque converter. Oil from the torque converter flows to the retarder control valve (if equipped), the flywheel, and to the transmission case. The flywheel scavenge pump pumps oil to lubricate the drive shaft bearing. The transmission scavenge pump pumps oil from the transfer gear case to the differential and bevel gear case.
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Text Reference
1
3
2
55
On the 637G Tractors, the two section transmission pump (1) is mounted in the transfer gear case located at the rear of the tractor. The two sections of the pump are the transmission scavenge section (2) and the charging section (3). The scavenge section of the pump is used to scavenge the oil from the bottom of the transfer gear case. Oil is pulled from the case through a scavenge line screen and is sent to the differential and bevel gear case. The transmission hydraulic system is charged by oil flow from the charge section of the pump. The charging pump section pulls oil from the differential and bevel gear case through a magnetic screen located below the transmission pump. Oil flow is directed through the transmission oil filter to the pressure control group. The oil from the pressure control group flows in two directions. Part of the oil flows to the transmission clutches. The remaining oil flows to the torque converter inlet valve.
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Text Reference
2
1
3 2 4
56
Oil flows from the transmission filter (1) to the upshift and downshift solenoids and the transmission hydraulic controls. The solenoids and hydraulic controls are located under the transmission covers (2). Excess oil flows from the transmission hydraulic controls and lubricates the transmission and transfer gears. The oil eventually falls to the bottom of the transmission case and is scavenged by the first section of the transmission pump. Transmission pump pressure can be measured at the transmission pump pressure tap (3). The transmission oil S•O•S tap (4) is located above the transmission pump.
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Text Reference
2 1 3
57
The torque converter outlet pressure tap (1) and the transmission lubrication pressure tap (2) are located on the left side of the transmission in front of the transmission cover (3).
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1
Text Reference
2 5
4
3
58
This view of the tractor transmission shows the upshift solenoid (1), the downshift solenoid (2), and the priority valve (3). Also visible in this view is the transmission oil filter (4) and the transmission pump pressure tap (5).
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Text Reference
6
5
4
1
2
3
59
This view shows the selector and pressure control valve group components with the transmission top cover removed. Visible in this view are: - Upshift solenoid (1) - Downshift solenoid (2) - Transmission pump pressure tap (3) - Selector valve group (4) - Transmission lube relief valve (5) - Transmission clutch pressure taps (6)
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Text Reference
WHEEL TRACTOR-SCRAPER SCRAPER POWER TRAIN COMPONENTS Diesel Engine
Torque Converter
Retarder (Optional)
Final Drive
Differential
Pinon Gear
Transmission
Drive Shaft
60
Scraper Power Train This illustration shows the major components of the 637G Wheel Tractor-Scraper power train. Power flows from the C9 engine to the torque converter. If the scraper is equipped with the optional retarder, power flows from the torque converter to the retarder. Power flows through the retarder to the power shift transmission. Power flows from the transmission through the transfer gears, drive shaft, and axles to the final drives and wheels.
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Text Reference
637G SCRAPER CATERPILLAR MONITORING SYSTEM 1
3
6
8 °c
Kpa
Miles
5 9 Km
Kph
Display Module (Cab)
Liter Serv Code X10
Cat Data Link
Action Lamp
Engine Oil Pressure Switch
Alternator "R" Terminal Engine Coolant Temperature Sender
Diagnostic Connector
Converter Oil Temperature Sender
Harness Code Plug
61
Transmission operation is controlled by the Scraper Transmission ECM. The ECM is located behind the fuel tank at the rear of the scraper bowl. The scraper Transmission ECM makes decisions based on information received by the tractor Transmission/Chassis ECM. The tractor transmission switch tells the tractor transmission control what tractor transmission gear is engaged. The tractor Transmission/Chassis ECM sends this information to the Scraper Transmission ECM. The scraper transmission determines whether a gear shift is required. If a scraper gear shift is necessary to keep the scraper transmission synchronized with the tractor transmission, the scraper Transmission ECM sends a current to ENERGIZE the synchronization solenoid.
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Text Reference
The scraper Transmission ECM controls the scraper transmission, in response to inputs from the tractor Transmission/Chassis ECM, scraper location code plug, and the scraper actual gear position sensor. Input components to the scraper Transmission ECM via the tractor Transmission/Chassis ECM include: - ECM location code plug - Tractor transmission gear position sensor - Tractor transmission output speed sensor - Key start switch - Tractor transmission neutral/run switch Outputs from the scraper Transmission ECM go to the following components and indicators: - CAT Monitoring System - Upshift solenoid - Downshift solenoid - Sync solenoid - Starter relay
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Text Reference
62
The scraper Transmission ECM (arrow) is located behind the fuel tank at the rear of the scraper bowl.
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Text Reference
1 2
5 3
6 4
63
Several scraper transmission hydraulic components are visible in this view. The transmission hydraulic components include: - Transmission hydraulic control valve containing the selector valve and the pressure control valve (1) - Synchronizing solenoid (2) - Transmission hydraulic oil sampling valve (3) - Transmission hydraulic oil filter (4) - Upshift solenoid (5) - Downshift solenoid (6) The 637G Scraper uses an automatic power shift transmission. The transmission provides four speeds in FORWARD and one speed in REVERSE. The transmission is not equipped with ICM hydraulic controls as are used in the tractor transmission.
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Text Reference
1
3
2
64
This view from below the scraper shows the transfer gear case (1) and the differential (2). Also visible is the ejector cylinder (3).
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Text Reference
1
3
2
4
65
This view shows the following scraper drive train components: - Wheel and final drive (1) - Drive shaft yoke (2) - Transfer gear case (3) - Differential (4)
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Text Reference
637G SCRAPER TRANSMISSION HYDRAULIC SYSTEM Oil Filter
Upshift Solenoid
Downshift Solenoid
Synchronizing Solenoid
Transmission Hydraulic Controls
Transmission Charge Pump
To Transmission Clutches
Magnetic Screen Scavenge Pump
Transmission Lubrication
Scavenge Screen
Hydraulic Oil Tank
Torque Converter
Oil Cooler
Lubrication Relief Valve
Transmission Case Reservoir
66
This view illustrates the oil flow through the 637G Scraper transmission hydraulic system components. The transmission charge pump draws oil from the hydraulic oil tank through a magnetic screen. The charge pump sends the oil through the transmission oil filter to the priority valve in the transmission hydraulic controls. Oil in the transmission flows to the selector valve. The transmission selector valve directs oil to the transmission clutches for gear engagement. Oil also flows to the torque converter, through the oil cooler and to the transmission lubrication relief valve. Some of this oil is used for planetary gear lubrication and the remaining oil flows to the transmission case reservoir. The scavenge pump pulls the oil from the transmission case reservoir through a magnetic screen and sends the oil back to the tank.
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Text Reference
637G SCRAPER TRANSMISSION CLUTCH ENGAGEMENT CHART Transmission Speed
Engaged Clutches
Reverse
1 and 4
Neutral
3
First Speed
2 and 5
Second Speed
1 and 5
Third Speed
2 and 3
Fourth Speed
1 and 3
67
This table shows the clutch engagement for each scraper transmission speed. The transmission planetary group consists of five planetary and clutch sets for a high/low forward speed arrangement. Low speed is provided by clutch No. 5. High speed is provided by clutch No. 3. REVERSE is provided by clutch No. 4. The directional clutches are Clutches 1 and 2. A speed and a direction clutch must be engaged for each speed. Clutches 3, 4, or 5 engage first. Clutches 1 and 2 engage last. All transmission speeds are full converter drive to permit complete synchronization with the direct drive speeds of the tractor.
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Text Reference
630G SERIES WHEEL TRACTOR-SCRAPERS HYDRAULIC SYSTEM Push-pull Cylinder (637G)
Ejector Cylinder
Cushion Hitch Cylinder
Bowl Cylinders
Apron Cylinder
Auger Motor
Charge Pump
Push-pull Control Valve
Cushion Hitch Valve
Implement Control Valve
Pilot Solenoid and Pressure Reducing Valve
Auger Pump Cushion Hitch Pump
To Steering Control Valve
Implement Pump
Steering Pump
68
IMPLEMENT HYDRAULIC SYSTEM The 637G Wheel Tractor-Scrapers are equipped with an Implement Electronic Control System. The implement control levers, used in earlier direct linkage type systems have been combined into a single joystick control. The pilot control valve and associated hardware have been eliminated. A Transmission/Chassis Electronic Control Module (ECM) receives and processes inputs and generates outputs to control the implement system. The 637G Implement Electronic Control System includes a pilot hydraulic system and a main hydraulic system. The pilot system controls the functions of the main control valve. The pilot system consists of the electronic system and the pilot hydraulic system.
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The Transmission/Chassis ECM sends outputs to: -
Gear hold light Ejector return light Tractor mode select light Scraper mode select light Apron float light Pilot supply solenoid Cushion-hitch solenoid Ejector forward solenoid Ejector reverse solenoid Bowl up solenoid Bowl down solenoid Bail solenoid Apron raise solenoid Apron lower solenoid Auger forward solenoid Auger reverse solenoid
Text Reference
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Text Reference
630G SERIES WHEEL TRACTOR-SCRAPER IMPLEMENT CONTROL SYSTEM Transmission/ Chassis ECM Hydraulic Oil Temp Sensor
Implement Control Lever
Pilot Supply Solenoid
Auger Slip Limiter Switch
Push-pull Solenoid Cushion-hitch Solenoid
Auger Reverse Switch
Ejector Forward Solenoid
Ejector Cylinder Pressure Sensor
Ejector Reverse Solenoid Bowl Up Solenoid
Auger Pump Case drain Filter Switch
Bowl Down Solenoid Apron Raise Solenoid
Auger Charge Pump Filter Switch
Apron Lower Solenoid
Auger Motor Case Drain Filter Switch
Auger Forward Solenoid Auger Reverse Solenoid
Gear Hold Light Ejector Return Light
Tractor Mode Select Light
Apron Float Light
Scraper Mode Select Light
69
The Transmission/Chassis ECM receives inputs from the implement control lever position sensors and various other sensors and switches as shown in this view. The ECM processes the input signals and sends corresponding output signals to the implement control solenoids and various indicators. The inputs to the Transmission/Chassis ECM are: -
Implement control lever position sensors Implement control lever switches Auger slip limiter switch Auger reverse switch Ejector cylinder pressure sensor Auger pump case drain filter bypass switch Auger charge pump filter bypass switch Auger motor case drain filter bypass switch Hydraulic oil temperature sensor
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Text Reference
The pilot hydraulic system consists of the cushion-hitch pump which provides the pilot oil supply, the pilot solenoid and pressure reducing valve, and the pilot actuator valves. The pilot actuator valves are mounted on the main control valve. The main hydraulic system consists of the implement and steering pump, the implement control valve, an ejector cylinder, two bowl cylinders, and an apron cylinder. The implement electronic control system also controls the following systems: - Cushion-hitch Hydraulic System (standard) - Auger Hydraulic System (optional) - Push-Pull Hydraulic System (optional on 637G)
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Text Reference
630G SERIES HYDRAULIC SYSTEM COMPONENTS Hydraulic Tank
Pilot Solenoid and Pressure Reducing Valve Implement Control Valve Joystick
Apron Cylinder Bowl Cylinder
Cushion Hitch Pump
Transmission/ Chassis ECM
Ejector Cylinder
Implement Pump
70
Implement System Components This illustration shows the location of the major components of the electronically controlled implement system on the 637G Wheel Tractor-Scrapers. The main electronic system components are the Transmission/Chassis ECM, the pilot control actuator solenoids (located on the main control valve), and the implement control lever. The implement control lever contains lever position sensors and switches which send input signals to the Transmission/Chassis ECM. The main hydraulic system components are the implement pump, implement control valve, pilot solenoid and pressure reducing valve, cushion-hitch pump (pilot oil supply), hydraulic tank, ejector cylinder, apron cylinder, and bowl cylinders.
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Text Reference
2
4 3 5
1
71
The implement control lever (1) is located on the right console in the cab. The implement control lever contains two position sensors, located at the base of the lever, which send PWM input signals to the Transmission/Chassis ECM. The ECM processes the signals and sends corresponding output signals to energize or de-energize the bowl and ejector pilot actuator solenoids. Forward and backward implement lever movement controls bowl RAISE and LOWER. Left and right implement lever movement controls ejector EJECT (forward) and RETURN. The thumb lever (2) also contains a position sensor that sends a PWM input signal to the Transmission/Chassis ECM. The ECM processes the signal and sends a corresponding output signal to the apron pilot actuator solenoid. The left button (3) activates or deactivates transmission hold. The right button (4) controls the cushion-hitch. The trigger switch (5) controls the auger or the bail on the 637G model.
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Text Reference
2
1 3
4
72
This view shows the hydraulic oil tank, located on the right side of the machine. The hydraulic tank oil filler cap (1) is located on the top of the tank. The oil filter, located inside the tank is accessible from the top of the hydraulic oil tank. To access the filter remove the filter cover (2). The engine air precleaner bracket (3) is bolted to the top of the filter cover. Also visible in this view is the breaker relief valve (4), which opens when the tank pressure reaches 69 ± 14 kPa (10 ± 2 psi).
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3
Text Reference
7
8
5 1
6 2 4
73
The two-section, vane type, implement/steering pump (1) is mounted on the front of the transfer gear case (2). The rear section of the pump (toward front of machine) sends oil to the steering control valve and the front section of the pump (toward rear of machine) sends oil to the implement control valve. The pilot solenoid and pressure reducing valve (3) directs oil from the cushion-hitch pump (4) to the implement control valve pilot actuators and reduces cushion-hitch pump pressure to pilot pressure. Pilot pressure is limited to 3450 ± 250 kPa (500 ± 35 psi). When the pilot supply solenoid (5) is energized by a signal from the Transmission/Chassis ECM, pilot oil is directed to the implement control valve. Also visible in this view is the pilot oil filter (6), implement hydraulic system supply pressure tap (7), and the steering hydraulic system supply pressure tap (8).
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Text Reference
1 3 2
74
The 637G implement control valve (1) is located on the left side of the tractor between the hitch and the left wheel fender. The implement control valve contains three valve spools which direct implement pump oil to the ejector cylinder, bowl cylinders, and apron cylinder. When the implement control lever is moved from the HOLD position, an electrical signal is sent from the Transmission/Chassis ECM to a pilot actuator solenoid (2). One actuator solenoid is visible in this view. The solenoids activate the pilot control actuators (3) which direct pilot oil to shift the implement control valve spools.
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Text Reference
5
6 3
4 2
8 1 9 7
75
In this view of the implement control valve off the machine, the following components are visible: - Bowl lower solenoid valve (1) - Bowl raise solenoid valve (2) - Apron lower solenoid valve (3) - Apron raise solenoid valve (4) - Ejector eject solenoid valve (5) - Ejector return solenoid valve (6) - Main relief valve (7) - Pump oil supply port (8) - Oil return port (9)
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Text Reference
3
1 2
76
This view shows the implements on a 637G Wheel Tractor-Scraper in the standard configuration with a bowl (1), an apron (2), and an ejector (3). The bowl raises and lowers to allow loading and unloading. The ejector pushes the load out of the machine. The apron controls the amount of bowl opening during loading and ejecting.
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Text Reference
2
1
3 4
77
The ejector cylinder (1) is located at the rear of the scraper, just above the rear axle. As the ejector cylinder rod (2) extends, it moves the ejector blade (3) forward. The ejector blade is suspended on three sets of rollers (4). Two rollers are visible in this view.
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Text Reference
4 2 1
6
5
3
78
The ejector speed change valve (1) is mounted to a bracket (not visible), which is bolted to the ejector cylinder (2). The ejector speed change valve controls ejector forward speed by controlling oil flow from the rod end of the ejector cylinder. The ejector speed change valve inlet and outlet lines are: - Pump supply line (3) - Outlet to head end of cylinder (4) - Outlet to rod end of cylinder (5) - Common rail line (6)
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Text Reference
4
2
5
6 1 7
3
6
8 9
79
The head end of the bowl cylinders (1) are mounted to the front of the scraper frame and the rod end of the bowl cylinders (2) are connected to the bowl (3). The bowl cylinders raise and lower the bowl. Also shown are the carry and quick-drop check valves (4) mounted on the head end of the bowl cylinders. The carry and quick-drop check valves direct oil from the rod end of the bowl cylinders to the head end of the bowl cylinders to increase bowl lowering speed. The apron cylinder (5) raises and lowers the apron. The head end of the apron cylinder is attached to the scraper frame and the rod end of the cylinder is attached to a two-piece link (6) that is connected to the apron (7) and scraper gooseneck. The apron sequence valve (8) is located inside the front of the scraper frame and can be accessed by removing a cover (9) on the right side of the scraper frame. The apron sequence valve directs oil from the rod end of the apron cylinder to the head end of the cylinder when an outside force contacts the apron.
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631G / 637G HYDRAULIC SYSTEM
Bowl Cylinder
Carry and Quick-drop Check Valve
HOLD Auger Relief Valve
Text Reference
Bowl Cylinder
Carry and Quick-drop Check Valve
Apron Sequence Valve
Apron Cylinder
Ejector Cylinder APRON LOWER
RETURN
BOWL LOWER
Ejector Speed Change Valve From Cushion-hitch Pump
Ejector Pressure Sensor Snubber Main Relief Valve Pilot Solenoid and Pressure Reducing Valve
APRON RAISE
EJECT
BOWL RAISE Pilot Filter Implement Control Valve
From Implement Pump
To Pump Suction And Drain
80
Hydraulic System Operation This schematic shows the oil flow in the 637G implement hydraulic system in the standard configuration with the engine running and implements in HOLD. In the pilot system, oil from the cushion-hitch pump flows to the pilot solenoid and pressure reducing valve. The pilot solenoid and pressure reducing valve consists of a solenoid valve and a pressure reducing valve. The solenoid valve is controlled by the Transmission/Chassis ECM and controls oil flow from the cushion-hitch pump to the pilot system. The pilot solenoid is de-energized during engine start-up, which blocks oil flow to the pilot system. When the engine is running, the solenoid is energized which allows oil to flow from the cushion-hitch pump to the pilot system. The pressure reducing valve limits the pilot system oil pressure to 3450 ± 250 kPa (500 ± 35 psi).
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Text Reference
The implement pump provides oil flow to the implement control valve. When the control valve spools are in the HOLD position, oil flows past the main relief valve and through the open-center control valves to the tank. The main relief valve opens to the tank when the main system pressure reaches approximately13800 kPa (2000 psi). In the HOLD position, oil flow to the cylinders and oil flow from the cylinders is blocked at the main control valve spools. NOTE: A relief valve is located between the head end of the apron cylinder and the tank on machines equipped with an auger. The relief valve directs oil from the head end of the apron cylinder to the tank if the apron contacts the apron stop bracket or if the bowl is lowered with the apron against the stop bracket.
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631G / 637G HYDRAULIC SYSTEM BOWL LOWER Auger Relief Valve
Text Reference
Carry and Quick-drop Check Valve
Bowl Cylinder
Carry and Quick-drop Check Valve
Bowl Cylinder
Apron Sequence Valve
Apron Cylinder
Ejector Cylinder
APRON LOWER
RETURN
BOWL LOWER
Ejector Speed Change Valve From Cushion-hitch Pump
Snubber Ejector Pressure Sensor
Main Relief Valve Pilot Solenoid and Pressure Reducing Valve APRON RAISE
EJECT
BOWL RAISE Pilot Filter Implement Control Valve
From Implement Pump
To Pump Suction and Drain
81
When the implement control lever is moved to the BOWL LOWER position, the bowl position sensor sends a PWM signal to the Transmission/Chassis ECM. The ECM sends a signal to the bowl lower solenoid located on the implement control valve. The bowl lower solenoid drains pilot oil to shift the bowl spool to the BOWL LOWER position. Pump supply oil is directed through the common oil passage to the carry and quick-drop check valve, to the rod end of the apron cylinder, and to the rod end of the ejector cylinder. Oil in the head end of the apron cylinder and oil in the head end of the ejector cylinder is blocked. Oil in the head end of the bowl cylinders extends the bowl cylinders to lower the bowl. Oil from the rod end of the bowl cylinders passes through the carry and quick-drop check valve, to the main control valve, and to the tank. When the implement control lever is released, the bowl control valve spool returns to the HOLD position, the oil flow is blocked, and the bowl stops moving.
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Text Reference
Z
631G / 637G HYDRAULIC SYSTEM BOWL QUICK-DROP Auger Relief Valve
Quick-drop Valve
Quick-drop Valve
Bowl Cylinder
Bowl Cylinder
Apron Sequence Valve
Apron Cylinder
Carry Check Valve
Carry Check Valve
Ejector Cylinder APRON LOWER
RETURN
BOWL LOWER
Ejector Speed Change Valve From Cushion-hitch Pump
Ejector Pressure Sensor Snubber
Main Relief Valve
Pilot Solenoid and Pressure Reducing Valve APRON RAISE
EJECT
BOWL RAISE Pilot Filter Implement Control Valve
From Implement Pump
To Pump Suction and Drain
82
When the operator moves the implement control lever to the full forward (detent) position, the QUICK-DROP function is activated. The bowl position sensor sends a PWM signal to the Transmission/Chassis ECM. The ECM sends a signal to the bowl lower solenoid. The bowl lower solenoid drains additional pilot oil to shift the bowl spool and the bowl spool moves up to the QUICK-DROP position. Pump supply oil is directed through the carry and quick-drop check valve to the head end of the bowl cylinders, which lowers the bowl. At the same time, oil is vented from the spring cavity of the quick-drop valves and the check valves to the tank. Oil from the rod ends of the bowl cylinders opens the carry check valves and the quick-drop valves. Oil flows directly from the rod end of the bowl cylinders to the head end of the bowl cylinders. With the oil flowing directly from the rod end of the cylinders to the head end of the cylinders the bowl lowers at a faster rate.
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631G / 637G HYDRAULIC SYSTEM APRON RAISE Auger Relief Valve
Text Reference
Carry and Quick-drop Check Valve
Bowl Cylinder
Carry and Quick-drop Check Valve
Bowl Cylinder
Apron Sequence Valve
Apron Cylinder
Ejector Cylinder
APRON LOWER
RETURN
BOWL LOWER
Ejector Speed Change Valve From Cushion-hitch Pump
Ejector Pressure Sensor Snubber Main Relief Valve
Pilot Solenoid and Pressure Reducing Valve APRON RAISE
EJECT
BOWL RAISE Pilot Filter Implement Control Valve
From Implement Pump
To Pump Suction and Drain
83
When the thumb lever on the implement control lever is moved to the APRON RAISE position, the thumb lever position sensor sends a PWM signal to the Transmission/Chassis ECM. The ECM sends a corresponding output signal to energize the apron raise pilot actuator solenoid. The apron raise pilot actuator drains oil from the bottom end of the apron valve spool to the tank and the apron valve spool moves down to the APRON RAISE position. The apron spool directs oil flow to the head end of the apron cylinder, which raises the apron. Oil from the rod end of the apron cylinder is directed to the tank. The apron spool also directs oil to the sequence valve. The sequence valve acts as both a bypass valve and a relief valve when an outside force moves the apron. When oil pressure in the rod end of the apron cylinder exceeds approximately 8625 kPa (1250 psi), the relief valve in the apron sequence valve opens. Oil flows from the head end of the apron cylinder to the rod end of the apron cylinder which lifts the apron.
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631G / 637G HYDRAULIC SYSTEM APRON FLOAT Auger Relief Valve
Text Reference
Carry and Quick-drop Check Valve
Bowl Cylinder
Carry and Quick-drop Check Valve
Bowl Cylinder
Apron Sequence Valve
Apron Cylinder
Ejector Cylinder
APRON LOWER
RETURN
BOWL LOWER
Ejector Speed Change Valve From Cushion-hitch Pump
Ejector Pressure Sensor Snubber Main Relief Valve
Pilot Solenoid and Pressure Reducing Valve EJECT
APRON RAISE BOWL RAISE
Pilot Filter Implement Control Valve
From Implement Pump
To Pump Suction and Drain
84
When the thumb lever on the joystick is moved to the APRON FLOAT position, the thumb lever position sensor sends a PWM signal to the Transmission/Chassis ECM. The ECM sends a corresponding output signal to energize the apron lower pilot actuator solenoid. The pilot actuator then drains additional oil, moving the spool to the APRON FLOAT position. When the spool is in the APRON FLOAT position, pump oil is directed through the common oil passage to the carry and quick-drop check valve, to the rod end of the apron cylinder, and to the rod end of the ejector cylinder. Oil in the rod ends of the bowl cylinders and oil in the head end of the ejector cylinder is blocked. Pump oil is directed to both the rod end of the apron cylinder and the head end of the apron cylinder and to the tank. Since supply oil is also open to the tank, system pressure is reduced to both ends of the cylinder. When the apron is in the APRON FLOAT position, movement of the apron is controlled by gravity and the weight of the apron itself.
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631G / 637G HYDRAULIC SYSTEM EJECTOR EJECT Auger Relief Valve
Text Reference
Carry and Quick-drop Check Valve
Bowl Cylinder
Carry and Quick-drop Check Valve
Bowl Cylinder
Apron Sequence Valve
Apron Cylinder
Ejector Cylinder Directional Valve APRON LOWER
RETURN
BOWL LOWER
Pilot Valve Ejector Speed Change Valve From Cushion-hitch Pump
Ejector Pressure Sensor Snubber Main Relief Valve
Pilot Solenoid and Pressure Reducing Valve APRON RAISE
EJECT
BOWL RAISE Pilot Filter Implement Control Valve
From Implement Pump
To Pump Suction and Drain
85
When the operator moves the implement control lever to the left (EJECT) position, the ejector position sensor sends a PWM signal to the Transmission/Chassis ECM. The ECM sends a signal to energize the eject pilot actuator solenoid. The eject pilot actuator drains pilot oil from the bottom end of the ejector spool and the ejector spool moves down to the EJECT position. Pump supply oil is directed to the head end of the ejector cylinder, which moves the ejector forward. Pump supply oil is also directed into the speed change valve. Oil from the rod end of the ejector cylinder flows into the ejector speed change valve. The speed change valve controls the oil flow from the rod end of the ejector cylinder. As the ejector moves forward with the scraper bowl empty and little or no resistance is present, the speed control valve causes an increase in the ejector cylinder rod speed. Oil flowing to the head end of the ejector cylinder also flows to the bottom of the directional valve and to the left end of the pilot valve.
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Text Reference
When system oil pressure is below approximately 12750 kPa (1250 psi), the oil present at the left side of the pilot valve is not enough to overcome the spring force. The oil pressure at the bottom of the directional valve raises the valve, and oil from the rod end of the ejector cylinder is directed to the head end of the cylinder. Ejector forward speed increases. The oil in the spring cavity at the top of the directional spool is connected through the pilot valve to the tank. As the ejector moves forward with the scraper bowl loaded, the speed control valve causes a decrease in the ejector cylinder rod speed. Oil flowing to the head end of the ejector cylinder also flows to the bottom of the directional valve and to the left side of the pilot valve. When system oil pressure reaches approximately 12750 kPa (1250 psi), the oil present at the left side of the pilot valve moves the pilot valve to the right which directs pump oil to the top of the directional valve. The directional valve lowers and oil from the rod end of the ejector cylinder is directed through an orifice in the directional valve to the tank. Ejector forward speed decreases. When most of the load has been ejected, and the system pressure decreases below 6030 kPa (875 psi) the ejector forward speed increases.
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Text Reference
1
6 6 4
3
10
5
5
2 2
7
7
8
4
11 9
86
Cushion-Hitch Hydraulic System The cushion-hitch system is standard on the 637G Wheel Tractor-Scrapers. The cushion-hitch minimizes vertical movements of the machine. The top views show the left and right sides of the cushion-hitch. The accumulators (1), located on the right side of the machine, dampen machine movement and provide a constant oil supply to the load cylinder (2). The head end of the load cylinder is connected to the tractor bracket assembly (3) and the rod end is connected to the scraper hitch assembly (4). The load cylinder lifts the scraper hitch assembly off the tractor bracket assembly in CUSHION RIDE mode. The lower link (5) and the upper link (6) provide the mechanical link between the tractor and the scraper hitch assembly.
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Text Reference
The scraper hitch assembly is attached to the scraper gooseneck (7). The connection between the hitch assembly and the gooseneck provides the pivot point between the tractor and scraper. The leveling valve (8) directs oil from the cushion-hitch pump (9) to the load cylinder. The cushion-hitch pump supplies oil to the leveling valve and provides the pilot oil supply to the implement hydraulic system. The upper and lower links are lubricated through the lubrication points (10) located in front of the accumulators. The cushion-hitch is operated from the cushion-hitch button (11) on the implement control lever in the cab. NOTE: The cushion-hitch pump is mounted on the transfer gear case at the rear of the tractor on tractors without an auger as shown here. The cushion-hitch pump is mounted on the transfer gear case below the auger pump on tractors equipped with an auger.
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Text Reference
Load Cylinder
CUSHION-HITCH HYDRAULIC SYSTEM LOCKDOWN
Directional Spool
To Pilot Solenoid and Pressure Reducing Valve Accumulator Valve Stem
Enable Valve Leveling Spool
Cushion-hitch Pump Leveling Valve To Drain and Pump Section
87 When the engine is running and the cushion-hitch switch is OFF, the cushion-hitch solenoid is DE-ENERGIZED and the cushion-hitch system is in the LOCKDOWN mode. The scraper is in a down position in relation to the tractor, which causes the leaf spring linkage to move the leveling spool to the LOCKDOWN position. Oil from the cushion-hitch pump flows to the leveling spool, the accumulator valve stem, and the cushion-hitch solenoid valve. Oil is blocked at the solenoid valve. The leveling spool directs the pump oil to the accumulator and the directional spool. When the accumulator oil pressure increases to approximately 16000 kPa (2320 psi), the pump pressure compensator valve destrokes the pump to stabilize the system pressure. Spring force moves the directional spool to the right which directs pump oil flow to the rod end of the load cylinder and from the head end of the load cylinder to the tank. The load cylinder retracts and the scraper lowers. Pump oil flow to the accumulator valve stem moves the valve up, which blocks pump oil and accumulator oil from returning to the tank. When the engine is off or pump oil flow stops, spring force moves the accumulator valve stem down, which allows oil in the accumulator to flow to the tank.
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Text Reference
Load Cylinder
CUSHION-HITCH HYDRAULIC SYSTEM CUSHION RIDE
Directional Spool
To Pilot Solenoid and Pressure Reducing Valve Accumulator Valve Stem
Enable Valve Leveling Spool
Cushion-hitch Pump Leveling Valve To Drain and Pump Section
88
When the engine is running and the cushion-hitch switch is ON, the cushion-hitch solenoid is ENERGIZED and the cushion-hitch system is in the CUSHION RIDE mode. The solenoid valve directs pump oil to the end of the directional spool. The directional spool moves to the left which allows oil to flow to the head end of the load cylinder and the load cylinder extends. When the load cylinder extends, the front of the scraper is lifted off the tractor and the cushion-hitch is in the CUSHION RIDE mode. When the scraper is lifted off the tractor, the leaf spring attached to the lower link pulls the leveling spool down (to the left in the schematic). The leveling spool blocks pump oil flow to the accumulator. The hydraulic oil between the head end of the load cylinder and the accumulator dampens the vertical movement between the tractor and the scraper. The leveling spool will move to the LOWER position if an external shock moves the scraper up in relation to the tractor. In the LOWER position, the leveling spool allows accumulator oil to flow to the tank.
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Text Reference
6
3
5 8
2
4
1 7 9
11 10
89
Auger Hydraulic System The auger attachment is available as an option. The top left view shows the auger (1), the auger gearbox (2), and the auger motor (3). The auger pump (4) is a variable displacement pump that provides oil flow to the auger motor. The auger charge pump (5) is mounted on the auger pump. The charge pump provides oil to the pump control valve (6) and makeup oil for the auger pump and motor circuit. The pump control valve is a solenoid operated valve that directs oil to the auger pump servo piston which controls the pump swashplate angle. The auger charge pump filter (7), auger pump case drain filter (8), and the cushion-hitch pump (9) are also visible in the top left view. The auger reverse switch (10) is located on the rear of the tractor to the left of the transfer gear case. The auger reverse switch activates the pump control solenoid which causes the pump to reverse oil flow and turn the auger motor in REVERSE. The auger is turned ON and OFF using the trigger switch (11) located on the front of the joystick in the cab. The auger operates at a single forward speed, but can be reversed to clear jams.
SERV1711-01 11/05
To Tank
- 109 -
Charge Relief Valve
Flushing Valve Group
631G / 637G AUGER HYDRAULIC SYSTEM
Auger Piston Motor Group
Charge Pump
Charge Filter
Text Reference
AUGER OFF
Por Valve Crossover Relief Valve Crossover Relief Valve
Pump Control Valve
Servo Piston
Filter
Filter To Drain and Pump Suction
Auger Pump
90
In the auger hydraulic system, the pump control valve controls the amount and direction of flow from the auger pump to the auger motor. Pump output (swashplate angle) is controlled by varying the amount of pressure available to the servo piston. Charge oil flows from the charge filter, through an orifice, to the Pressure Override (POR) valve. As long as system pressure remains below the pressure setting of the POR valve, oil will flow to the pump control valve. Charge oil flow is also directed to the external charge relief valve. During the neutral/stop condition, the system pressure in the closed loop will be limited by the external charge relief valve and the excess flow is returned to the tank. Charge oil also flows to the combination crossover relief and makeup valves. In neutral/stop, the crossover relief valves remain closed and the makeup valves meter a small amount of oil to both sides of the closed loop to make up oil lost due to normal leakage and lubrication.
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Text Reference
With the engine running and the auger OFF (as shown in this view), there is no signal to either end of the pump control spool and the spool stays in the centered or neutral position. With the control spool in the neutral position, charge pressure oil is present at both ends of the servo piston which holds the swashplate in the centered position or zero angle. With the swashplate in this position, the auger pump does not produce flow. With no pump output the auger motor does not turn. With the pump in NEUTRAL (swashplate at zero angle), the pump does not produce flow, but the oil in both lines to the auger motor is approximately at charge pressure because of the makeup valve function in the auger pump.
SERV1711-01 11/05
To Tank
- 111 -
Charge Relief Valve
Flushing Valve Group
AUGER ON
Por Valve
Crossover Relief Valve
Crossover Relief Valve
Pump Control Valve
631G / 637G AUGER HYDRAULIC SYSTEM
Auger Piston Motor Group
Charge Pump
Charge Filter
Text Reference
Servo Piston
Filter
Filter
Auger Pump
To Drain and Pump Suction
91
When the auger is turned ON, the Transmission/Chassis ECM sends a signal to the pump control valve which directs charge pump oil to the pump servo piston. The charge pressure oil at the servo piston causes the swashplate to tilt, which upstrokes the pump. As the swashplate begins to move, pump output flow is sent through the output port to the auger motor and the motor begins to turn. Return oil from the motor then flows back to the inlet of the drive pump in a continuous closed loop. In the high pressure side of the drive loop, output oil from the pump seats one of the crossover relief makeup valves. The makeup valve blocks flow through the valve since this oil pressure is higher than the charge pressure acting against the low side. Cool oil from the charge pump replenishes the system through the makeup portion of the crossover relief valve that is not held closed by high pressure oil. The makeup oil compensates for loop losses through the pump, motor leakage (case drain), and the low pressure side bleed off through the flushing valve.
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Text Reference
3 4
1 2
5
7
8
6
92
637G Push-Pull Hydraulic System The push-pull system is available on the 637G only. The push-pull system allows the 637G Wheel Tractor-Scraper to push or pull another wheel tractor-scraper. The bail (1) located on the front of the scraper, allows the 637G Wheel Tractor-Scraper to hook to another machine. The bail cylinder (2) raises and lowers the bail. The push plate (3) on the front of the tractor is used to push another wheel tractor-scraper and the hook (4) is used to pull a wheel tractor-scraper. The bail is lowered over the hook to provide a secure connection. A wheel tractor-scraper can be pushed by another machine at the rear push-pull block (5). The push-pull control valve (6), is located on the inside of the frame rail below the front of the cab. The push-pull control valve directs oil from the cushion-hitch pump to the bail cylinder.
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Text Reference
The solenoid valve (7) is located in front of the push-pull control valve. When energized by the Transmission/Chassis ECM, the solenoid directs oil from the cushion-hitch pump to the push-pull control valve. The bail is raised and lowered using the trigger switch (8) located on the implement control lever. NOTE: The bail is a two-tone (black and yellow) color. The two-tone color improves visibility of the bail centerline which aids bail/hook alignment. The two-tone color also reduces glare.
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Text Reference
PUSH-PULL HYDRAULIC SYSTEM BAIL LOWER
To CushionHitch Valve
To Pilot Press Supply Valve
Pressure Relief Valve
Push-pull Solenoid Valve
Line Relief Valve Directional Valve
Shuttle Valve
CushionHitch Pump
Bail Cylinder
Push-pull Control Valve
93
The cushion-hitch pump provides oil flow to the push-pull control valve and the push-pull control valve controls the oil flow to the bail cylinder. Oil from the cushion-hitch pump flows to the push-pull solenoid valve and through a check valve to the directional valve spool. When the push-pull trigger switch is pressed to move the bail to the LOWER position, the solenoid valve is de-energized. The solenoid valve directs oil from the cushion-hitch pump to the top of the directional spool. The directional spool moves down, which directs pump oil to the head end of the bail cylinder. Oil in the rod end of the cylinder flows through the shuttle valve to the tank. The bail cylinder extends and the bail moves to the LOWER position. The orifice in the shuttle valve limits the speed that the bail cylinder extends and thus the lowering speed of the bail. An external force pushing down on the bail shifts the shuttle valve up and allows increased oil flow from the rod end of the bail cylinder to the tank. An external force pushing up on the bail, when added to the pump flow, can produce a larger flow than the orifice to the pressure relief valve will allow. The pressure between the head end of the bail cylinder and the orifice will rise to the opening pressure of the line relief valve and excess flow will return to tank through the line relief valve.
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Text Reference
PUSH-PULL HYDRAULIC SYSTEM BAIL RAISE
To CushionHitch Valve
To Pilot Press Supply Valve
Pressure Relief Valve
Push-pull Solenoid Valve
Line Relief Valve Directional Valve
Shuttle Valve
CushionHitch Pump
Bail Cylinder
Push-pull Control Valve
94
When the push-pull trigger switch is pressed to move the bail to the RAISE position, the solenoid valve is energized. The solenoid valve directs oil from the top of the directional spool to the tank. Spring force moves the directional spool up, which directs pump oil to the rod end of the bail cylinder. Oil in the head end of the cylinder flows to the tank. The bail cylinder retracts and the bail moves to the RAISE position.
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To Implement Control Valve
630G SERIES STEERING HYDRAULIC SYSTEM
Text Reference
Implement Pump
Screen Group
Tank Steering Pump
Steering Control Valve
System Check and Relief Valve
Steering Cylinders Servo Cylinder
Steering Metering Pump
95
STEERING HYDRAULIC SYSTEM The 637G Wheel Tractor-Scraper steering hydraulic system includes the servo pilot circuit and the main steering circuit. The servo pilot circuit controls the movement of the valve spool in the steering control valve and consists of the steering metering pump, servo cylinder, and steering system check and relief valve. The check and relief valve is mounted on the steering control valve. When the steering wheel is turned, the steering metering pump sends pilot oil to the steering control valve, which directs main steering pump oil to the steering cylinders. The main steering circuit consists of the implement/steering pump, the steering control valve, and the steering cylinders. The steering control valve contains a pressure reducing valve which provides reduced oil (pilot oil) to the servo pilot circuit. The control valve also contains the steering system main relief valve. The implement/steering pump is a two-section pump. The steering section of the pump draws oil from the hydraulic tank and sends the oil to the steering control valve. The steering control valve directs the oil to the steering cylinders. The steering cylinders extend and retract to steer the machine.
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Text Reference
The secondary steering pump, if equipped, supplies oil to the steering system when the machine is moving forward if the engine stops or the main steering pump fails. INSTRUCTOR NOTE: The steering metering pump was previously known as the Hand Metering Unit (HMU).
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Text Reference
STEERING HYDRAULIC SYSTEM COMPONENTS Hydraulic Tank
Steering Metering Pump
Steering Control Valve
Servo Cylinder
Secondary Steering Pump
Steering Cylinder
Implement / Steering Pump
96
This view shows the location of the major steering system components. The servo pilot circuit components shown include the servo cylinder and steering metering pump. The steering system check and relief valve is mounted to the front of the steering control valve. The main steering circuit components shown include the implement/steering pump, steering control valve, and steering cylinders. The secondary steering pump is part of the secondary steering system (if equipped). The hydraulic tank is located below the platform in front of the tire on the right front side of the machine.
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Text Reference
2 3
1
4
6
5
7 7
97
The implement and steering pump (1) is mounted to the front of the transfer gear case at the rear of the tractor. The implement and steering pump is a two-section vane pump. The rear section (toward the front of the machine) is the steering pump and the front section (toward the rear of the machine) is the implement pump. Oil is sent from the steering pump to the steering control valve (2). Pressure from the steering pump can be checked at the supply pressure tap (3). The steering control valve is located below the cab on the frame rail. The steering control valve directs oil flow from the steering pump to the steering cylinders. The check and relief valve (4) is mounted to the steering control valve. The check and relief valve directs oil flow to the ends of the steering control valve spool. The right steering cylinder (5) and left steering cylinder (6) are connected between the tractor and the scraper to articulate the machine. Also visible are the mechanical stops (7) on the tractor and scraper.
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Text Reference
6
2 4
4 1 5 3
7 9
8
98
The steering metering pump (1) is located below the cab. The steering metering pump is connected to the steering column by a splined shaft. As the steering wheel is turned, oil is sent to the ends of the steering control valve directional spool. The steering metering pump is both a metering pump and a directional valve which contains two sections; the control section and the metering section. The metering section supplies oil flow and the control section directs oil to the steering control valve. The top right view as seen from below the steering control valve shows the check and relief valve (2) which is mounted to the steering control valve (3). The check and relief valve consists of two makeup valves (not visible), two crossover relief valves (4), and two pilot check valves (5). The makeup valves are both open to allow oil into the pilot system as makeup oil when the steering wheel is not being turned. As the wheel is turned, one makeup valve remains open to provide makeup oil into the pilot system. The crossover relief valves direct oil to the opposite side of the pilot circuit when one side of the pilot system exceeds the relief valve setting.
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Text Reference
The pilot check valves normally allow pilot oil flow in both directions in the check and relief valve. Also visible in this view is a plug (6) that can be removed to test pilot oil pressure at the pressure reducing valve. The bottom left view shows the servo cylinder (7) mounted at the top of the cushion-hitch on the left side of the machine. The servo cylinder is fastened between the left side "H-link" on the tractor and the rear cushion-hitch casting on the scraper. The servo cylinder moves when the machine articulates. Cylinder rod movement sends oil, as a hydraulic signal, through the servo pilot system. The optional secondary steering pump (8), is a two-section gear pump, mounted on the front differential case. The secondary steering pump provides hydraulic oil flow to operate the steering cylinders when the engine or steering pump fails. The secondary steering pump provides oil flow only when the machine is moving forward. A pressure tap (9) attached to the secondary steering pump can be used to check pump output oil pressure.
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Text Reference
Servo Cylinder
Steering Cylinders Pressure Reducing Tap
Left Turn Bleed Valve
Right Turn Bleed Valve
630G SERIES STEERING HYDRAULIC SYSTEM HOLD
Left Turn Bleed Valve Pilot Check Valve
Strainer Makeup Valve
Steering Metering Pump
Relief Valve Flow Control Valve Steering Control Valve Spool
Steering Control Valve
Pressure Reducing Valve
Relief Valve
Main Relief Valve
Pilot Check Valve
Check and Relief Valve Right Turn Bleed Valve
Steering Pressure Tap
From Implement Pressure Tap Implement/ Steering Pump
Vent to Atmosphere Tank
Pressure Switch (air Vacuum Breaker)
To Drain and Pump Suction
99
Steering System Operation This view shows the steering system in the engine running, NO TURN condition. Steering pump oil flows to the steering control valve. In the steering control valve, oil flows to the pressure reducing valve, which regulates the oil pressure to the pilot system. When the pilot system is first charged, both of the valves will open. If oil pressure on only one side of the pilot system decreases, the makeup valve for that side of the system will open. After the oil enters the pilot system through the makeup valves, oil flows to the servo cylinder, the crossover relief valves, and to the pilot check valves. Oil flows through the pilot check valves to the steering metering pump and to the ends of the steering control valve spool. Spring force and equal oil pressure at each end of the steering control valve spool keeps the spool in the centered position. With the steering control spool in the centered position, oil flows to both steering cylinders, through the flow control valve, and to the tank. The oil flowing to the steering cylinders in the NO TURN condition is maintained at a low back pressure, approximately 450 kPa (65 psi), by the shimmed spring shown below the flow control valve. This shortens the response time when a turn is initiated.
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Steering Cylinders
Text Reference
Servo Cylinder
Pressure Reducing Tap
Left Turn Bleed Valve
Right Turn Bleed Valve
Left Turn Bleed Valve
630G SERIES STEERING HYDRAULIC SYSTEM LEFT TURN
Pilot Check Valve
Strainer Makeup Valve
Steering Metering Pump
Relief Valve Flow Control Valve Steering Control Valve Spool
Pressure Reducing Valve
Relief Valve
Main Relief Valve
Pilot Check Valve
Check And Relief Valve
Steering Control Valve Right Turn Bleed Valve
Steering Pressure Tap
From Implement Pressure Tap
Implement / Steering Pump
Vent to Atmosphere
Tank
Pressure Switch (Air Vacuum Breaker)
To Drain and Pump Suction
100
When the steering wheel is turned left, the steering metering pump sends oil to the top of the steering control valve spool and to the pilot check valve. The spool moves down to the left turn position and directs steering pump oil to the head end of the right steering cylinder and to the rod end of the left steering cylinder. The machine articulates to the left. Oil from the rod end of the right steering cylinder and the head end of the left steering cylinder returns to tank. When the steering control valve spool moves down, steering pump oil is also directed through a strainer and orifice between the flow control valve and the main relief valve. The flow control valve closes and becomes the dump valve for steering pump oil flow if the maximum main relief valve pressure setting is reached. In the check and relief valve, oil flows through the pilot check valve to the crossover relief valve and the left side of the servo cylinder. Oil at the right end of the servo cylinder flows to the crossover relief valve and through the pilot check valve, out the right end of the steering control valve and to the steering metering pump. Since the pilot system is a closed system, the oil at the right end of the steering control valve is returned to the steering metering pump where the oil pressure to the metering section is maintained at 450 kPa (65 psi) by the check valve before being routed to the pump suction line.
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Text Reference
Servo Cylinder
Steering Cylinders Pressure Reducing Tap
630G SERIES STEERING HYDRAULIC SYSTEM
Right Turn Bleed Valve
Left Turn Bleed Valve
WITH SECONDARY STEERING HOLD
Left Turn Bleed Valve
Strainer
Steering Metering Pump
Relief Valve Flow Control Valve Steering Control Valve Spool Steering Control Valve
Relief Valve
Main Relief Valve
Check And Relief Valve
Right Turn Bleed Valve
Steering Pressure Tap
From Implement
Pressure Tap
Implement / Steering Pump
Vent To Atmosphere
Secondary Steering Pump
Tank
Pressure Switch (Air Vacuum Breaker)
To Drain and Pump Suction
101
This view shows the steering system with the engine off and the machine moving. When the engine is off, no oil flows from the main steering pump. The steering system oil is supplied by the secondary steering system. The secondary steering system consists of the secondary pump, diverter valve, and check valves. When the machine is moving, the differential ring gear turns the secondary pump. When main pump oil pressure decreases below 1240 kPa (180 psi), spring force moves the diverter valve. The diverter valve directs the secondary pump large section oil flow to combine with the secondary steering pump small section oil flow and pass through the check valve to the steering control valve. When the operator moves the steering wheel, secondary pump oil is used to steer the machine.
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Text Reference
630G SERIES WHEEL TRACTOR-SCRAPERS AIR SYSTEM AND BRAKES Tractor Actuator
Parking Brake Solenoid Valve
Retarder Control Valve
Tractor Wheel Brakes
Accessory Circuits
Scraper Wheel Brakes
Parking / Secondary Brake
Parking / Secondary Brake
Service Brake
Service Brake
Relay Valve
Service Brake Control Valve
Relay Valve
Air Reservoir
Air Reservoir
Air Reservoir
Scraper Actuator
Parking Brake Solenoid Valve
Air Reservoir
Air Dryer
AIR COMPRESSOR GOVERNOR
102
AIR SYSTEM AND BRAKES The 637G Wheel Tractor-Scraper brakes are controlled by an air system that operates the service brakes and the parking/secondary brakes. The service brakes are air activated and spring released. The service brakes have a split air circuit and each circuit has an air reservoir and a relay valve. The service brake control valve contains two sections that direct pilot air to the tractor air circuit and the scraper air circuit relay valves. If either service brake air circuit fails, the other circuit will stop the machine. The parking/secondary brakes are spring activated and released by air pressure. The parking/secondary brakes are activated manually with the parking brake knob in the cab. The parking/secondary brakes are activated automatically when the air system pressure is too low. The wheel brakes are shoe type brakes. There is a brake actuator at each wheel which engages and releases the brake shoes. The brake actuators use spring force to engage the parking/secondary brakes and air pressure to engage the service brakes.
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Text Reference
The 637G air system also supplies air to the retarder control valve and the accessory air circuits. The air system consists of the following air circuits: - Air charging circuit (gray) - Service brake circuit (pink) - Parking/Secondary brake circuit (yellow) - Optional retarder air circuit (orange) - Accessory air circuits (blue) • Differential lock circuit
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Text Reference
630G SERIES WHEEL TRACTOR TRANSMISSION ELECTRONIC CONTROL SYSTEM Transmission/ Chassis ECM
INPUT COMPONENTS
OUTPUT COMPONENTS
ECM Location Code
Cat Data Link Electronic Service Tool
Shift Lever Position Switch
Tractor Engine ECM
Transmission Gear Switch
Scraper Engine ECM Scraper Transmission ECM
Engine Output Speed Sensor Transmission Output Speed Sensor
Caterpillar Monitoring System
Key Start Switch Tractor Transmission Neutral / Run Switch
Upshift Solenoid
Downshift Solenoid
Parking Brake Switch Starter Relay
Pilot Supply Pressure Sensor Retarder Pressure Switch
Brake Air Supply Solenoid
Tractor Air Pressure Sensor Tractor Service Brake Pressure Switch
Tractor Park Brake Solenoid
Tractor Parking Brake Pressure Switch Scraper Park Brake Solenoid Scraper Air Pressure Sensor Scraper Service Brake Pressure Switch
Retarder Lamp
Scraper Parking Brake Pressure Switch
103
This view shows a partial list of the Transmission/Chassis Electronic Control System input and output components. The air and brake system electronic input and output components are highlighted in red. The Tractor Transmission/Chassis Electronic Control Module (ECM) controls the following functions relating to the air and brake system: - Brake air supply pressure - Parking/secondary brake activation - Parking brake logic - Air system warning via the Caterpillar Monitoring System - Parking brake warning via the Caterpillar Monitoring System - Overrides Control Throttle Shifting when brakes are engaged - Overrides Throttle Lock when brakes are engaged
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Text Reference
When the Transmission/Chassis ECM receives an input signal from any of the air pressure sensors, the ECM processes the signal and sends a corresponding output signal to the brake supply solenoid. The brake supply solenoid activates or deactivates the governor which controls the air supply pressure. When the Transmission/Chassis ECM receives an input signal from the parking brake switch, the ECM processes the signal and sends a corresponding output signal to the tractor and scraper parking brake solenoids to engage or release the parking/secondary brakes. When the Transmission/Chassis ECM receives a low pressure input signal from any of the air pressure sensors, the ECM processes the signal and sends a corresponding output signal to the tractor and scraper parking brake solenoids to engage the parking/secondary brakes. The Transmission/Chassis ECM will DE-ENERGIZE the parking brake solenoids and engage the parking/secondary brakes if the air pressure is below 380 ± 35 kPa (55 ± 5 psi). The ECM will ENERGIZE the parking brake solenoids and release the parking/secondary brakes if the air pressure is above 620 kPa (90 psi). When the Transmission/Chassis ECM receives a low pressure input signal from the tractor, scraper, or pilot pressure sensor, the ECM processes the signal and sends a corresponding output signal to the Caterpillar Monitoring System. The monitoring system flashes the air system lamp, the action lamp, and sounds the action alarm. The monitoring system will also display the air system pressure on the quad gauge module. When the Transmission/Chassis ECM receives a low pressure input signal from the tractor or scraper parking brake pressure switches, the ECM processes the signal and sends a corresponding output signal to the Caterpillar Monitoring System. The monitoring system flashes the parking brake lamp, the action lamp, and sounds the action alarm. The Transmission/Chassis ECM will override the control throttle shifting and throttle lock functions if the tractor service brake pressure switch, scraper service brake pressure switch, or retarder pressure switch closes.
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Text Reference
1
4 2
3
104
Air Charging Circuit The air charging system generates, dries, and stores pressurized air to operate the air and brake system. The air compressor (1) and the air compressor governor (2) are mounted on the rear of the tractor engine above the engine flywheel housing (3). The air compressor supplies air to the air dryer. The compressor is turned on and off by the air compressor governor. The governor can be adjusted by removing the cap (4) on top of the governor and turning an adjustment screw.
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Text Reference
1
2
3
105
The air dryer (1) is mounted on the front of the cab next to the cab air filter (2). The air dryer contains a desiccant cartridge which removes contaminants and moisture from the air system. The air dryer also contains a heating element which prevents moisture in the dryer from freezing in cold weather. Whenever the compressor is turned off, the air compressor governor provides air pressure to open the air dryer drain valve located at the bottom of the dryer. When the air dryer drain valve is open, the moisture stored inside the air dryer is drained through the drain hose (3).
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Text Reference
1
1 5 6 2
6
5
5 1
2
1
4 4
3
3
106
There are four air reservoirs, two on the tractor and two on the scraper. The air reservoirs store air from the compressor for distribution to the air system components. The tractor air reservoirs (1) are mounted on a panel (2) below the cab. The bottom (larger) air reservoir is a two-section air reservoir. One section stores air for the tractor and one section stores air for the scraper service brake air circuit. The scraper air reservoirs (not visible) are located inside the scraper frame behind covers (3) to the rear of each brake actuator (4). The scraper air reservoirs in the bottom views are looking toward the rear of the scraper. One-way check valves (5) are located on the input lines to the air reservoirs. The one-way check valves (not visible) on the scraper air reservoirs are located at the rear of the scraper reservoirs. Air from the compressor flows into the air reservoirs through the one-way check valves. An air relief valve (6) is located on the bottom tractor air reservoir. The relief valve limits air system pressure to 1034 ± 55 kPa (150 ± 8 psi).
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1
2 3
107
There are three tractor air reservoir drain valves (1) located inside the step leading to the cab. Two of the drain valves are visible in this view. The left scraper air reservoir drain valve (2) and right scraper air reservoir drain valve (3) can be accessed through a hole on each side of the scraper frame.
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Text Reference
1
3 2
108
There are three air pressure sensors on the 637G Wheel Tractor-Scrapers that send PWM signals to the Transmission/Chassis ECM. The tractor air pressure sensor (1) is located at the right front corner of the cab vertical mount. The scraper air pressure sensor (2) is located on the scraper air reservoir at the right rear scraper frame rail. The pilot air pressure sensor (3) is located below the cab. The Transmission/Chassis ECM uses the pressure sensor signals to perform the following functions: - Illuminate the brake air pressure indicator on the main display module, flash the action lamp, and sound the action alarm when the air system pressure is below 520 ± 35 kPa (75 ± 5 psi).
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Text Reference
- Automatically engage the parking brake if air pressure is below 380 ± 35 kPa (55 ± 5 psi). The Transmission/Chassis ECM will not allow the parking brake to be manually released until air system pressure is 620 kPa (90 psi). - Control the brake air supply solenoid. - Display the air pressure on the quad gauge module.
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Text Reference
1 2
5
4 3
109
Air Brake Circuits The 637G Wheel Tractor-Scrapers air brake circuits include the service brake circuit and the parking/secondary brake circuit. The service brakes are used to stop the machine during normal operation. The service brake pedal (1) is located on the floor of the operator’s station. Depressing the pedal engages the service brakes and releases the parking brake (if applied) using air pressure. The parking/secondary brakes are used to prevent the machine from moving when parked or stop the machine when the air system has malfunctioned. The parking/secondary brakes are on the same air circuit. The parking brakes are applied manually using the parking brake knob (2) located on the right console in the cab. When the knob is pulled up, the parking brake is engaged. The secondary brakes are automatically applied when air pressure is lost.
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Text Reference
When the parking brakes are engaged and the transmission is in NEUTRAL, the park brake ON indicator (3) will flash. If the air pressure in the parking/secondary brake system is below 380 ± 35 kPa (55 ± 5 psi), the park brake ON indicator will flash, the action alarm will sound, and the parking/secondary brakes will automatically engage. If the air pressure decreases below 520 ± 35 kPa (75 ± 5 psi), the air pressure indicator (4) will flash, the action alarm will sound, and the air gauge (5) will read in the red zone.
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Text Reference
1 2
6 6 3
4
5
5
110
The brake actuators are located near each wheel. The top views show the left tractor brake actuator (1) and right tractor brake actuator (2). The bottom views show the left scraper brake actuator (3) and right scraper brake actuator (4). Each brake actuator has two air chambers, the parking/secondary chamber (top) and the service brake chamber (bottom). The parking/secondary brakes are engaged by spring force and released with air pressure. Air from the compressor is sent to the top chamber of the brake actuator to release the parking/secondary brakes. When the service brake pedal is depressed, air flows to the service brake chamber and engages the service brakes. When the pedal is released, air is exhausted from the service brake chamber and the service brakes are released. When the brakes are engaged, the actuator rod (5) extends and moves the slack adjuster (6) down. The slack adjusters provide a link between the brake actuator rod and the brake camshaft. When the slack adjusters move down, the camshaft forces the brake shoes against the brake drum to slow or stop the machine. The slack adjusters also compensate for brake lining wear.
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Text Reference
4 5 6 1
3 2
111 The service brake control valve (1) is located below the cab. When the brake pedal is depressed, the service brake control valve directs air flow to the relay valves. The service brake control valve contains two sections. The upper section directs air to the tractor relay valve (2) and the lower section directs air to the scraper relay valve (3). The tractor service brake pressure switch (4) and the scraper service brake pressure switch (5) are located in the service brake air supply lines. The pressure switches send a signal to the Transmission/Chassis ECM when the brake pedal is depressed. The ECM sends a signal to deactivate the transmission control throttle shifting and throttle lock functions. The stop light switch (6) closes when the brake pedal is depressed and sends a signal to the lamp control module to illuminate the brake lights. The tractor relay valve is located above the tractor transmission. The scraper relay valve is located on the right side of the scraper to the rear of the brake actuator. The relay valves function as pilot operated control valves. Supply air pressure is available on one side of the relay valves. When the service brake pedal is depressed, pilot air is sent to the relay valves. The pilot air opens a spring loaded valve and allows supply air to flow to the brake actuators.
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Text Reference
6
1
4
9
5 8
3
2
7
112
There are two parking brake solenoid valves. The tractor parking brake solenoid valve (1) is located below the cab. The scraper parking brake solenoid valve (2) is located on the right side of the scraper to the rear of the brake actuator (3). The parking brake solenoid valves are energized and de-energized by the Transmission/Chassis ECM. When the parking brake solenoid valves are de-energized (valve closed) air is vented from the parking/secondary brake chamber and the parking/secondary brakes are engaged by spring force. The ECM will energize or de-energize the parking brake solenoid valve in response to inputs from the parking brake knob and the parking brake pressure switches. The tractor parking brake pressure switch (4) is located on the rear of the tractor above the transmission. The scraper parking brake pressure switch (5) is located on the right side of the scraper to the rear of the brake actuator. The pressure switches sense parking/secondary brake circuit pressure and send a signal to the Transmission/Chassis ECM when air pressure decreases below 380 ± 35 kPa (55 ± 5 psi). The ECM will close the parking brake solenoid valves and engage the parking/secondary brakes.
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Text Reference
The tractor quick release and holding valve (6) and the scraper quick release and holding valve (7) reduce the time needed to apply the parking/secondary brakes by providing a path to exhaust air from the brake actuator parking/secondary air chamber. The tractor double check valve (8) is located between the cab and the left side of the tractor engine and the scraper double check valve (9) is located on the right side of the scraper to the rear of the brake actuator. The double check valves prevent the parking/secondary brake piston and the service brake diaphragm in the brake actuators from being activated at the same time.
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Text Reference
5 3 2
1
4
6
113
Retarder Circuit The retarder control valve (1) and retarder lever (2) are located on the steering column. The retarder air control valve controls air pressure to the retarder circuit and the scraper torque converter lockup clutch. Pulling the retarder control lever backward toward the operator increases the air supply to the tractor retarder hydraulic control valve (3) and the scraper retarder hydraulic control valve (4). The tractor retarder hydraulic control valve is mounted to the engine flywheel housing (5) and the scraper retarder hydraulic control valve is located on the lower left side of the scraper transmission. The retarder hydraulic control valves direct oil flow to the tractor and scraper retarder to slow machine movement. The scraper retarder air control regulator (6) is located on the left side of the scraper engine in the air line between the retarder air control valve and the retarder hydraulic control valve.
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Text Reference
The scraper retarder air control regulator limits the air pressure to the scraper retarder hydraulic control valve to 450 ± 34 kPa (65 ± 5 psi). INSTRUCTOR NOTE: A complete discussion of the 630G Series Wheel TractorScrapers retarder operation is presented in Technical Instruction Module "631G/637G Wheel Tractor-Scrapers--Power Train Systems" (Form SERV2711).
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Text Reference
114
The retarder pressure switch is located at the right front corner of the cab vertical mount. The retarder pressure switch sends a signal to the Transmission/Chassis ECM when the retarder lever is moved to engage the retarder. The ECM sends a signal to de-activate the transmission control throttle shifting (CTS) and throttle lock functions. The Transmission/Chassis ECM uses the retarder pressure switch signal to perform the following functions: - Send a signal to the Engine ECM and Scraper Transmission ECM to de-activate the throttle lock function - De-activate CTS function - De-activate Rapid Downshift function - Use elevated shift points, which provide increased engine speed during downhill retarding for increased oil flow through the retarder oil circuit
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Text Reference
115
Accessory Circuits The air system also supplies air to the 637G Wheel Tractor-Scraper accessory circuits. The pressure protection valve (arrow), located below the cab, controls air flow to the accessory circuits. Air will not flow to the accessory circuits until the air pressure reaches 520 kPa (75 psi) which ensures there is sufficient air pressure to operate the brake circuits.
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Text Reference
1
3
2
116
The differential lock circuit allows the operator to manually lock the differential to reduce wheel slippage and improve traction. When either differential lock switch (1) on the floor of the cab is depressed, a signal is sent to the differential lock solenoid valve (2) located below the cab. When the differential lock solenoid valve is open, pressurized air is sent to the differential. The pressurized air unlocks the differential. The differential lock quick release valve (3) is located on the tractor differential case to the right of the transmission. The quick release valve reduces the time needed to release the differential lock by providing an exhaust source near the differential lock.
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Text Reference
630G SERIES AIR AND BRAKE SYSTEM ENGINE RUNNING
SCRAPER
TRACTOR
Brake Actuator
OPERATOR STATION
Air Dryer
Brake Actuator
Retarder Control Valve
Double Check Valve
Service Brake Control Valve
Pressure Protection Valve
Diff. Lock
Air Reservoir
Diff Lock Solenoid Valve
Park Brake Solenoid Valve
Quick Release Valve
Relay Valve Air Reservoir Brake Actuator
Park Brake Solenoid Valve
Air Reservoir
Double Check Valve Retarder
Brake Supply Solenoid Valve
Relay Valve
Brake Actuator
Governor
Retarder Valve Compressor
(637G ONLY)
117
Air and Brake System Operation When the engine is running, air from the compressor passes through the air dryer and through the one-way check valves to the tractor and scraper air reservoirs. The air reservoirs provide the air supply to the following components: - Service brake control valve: One section directs air to the tractor relay valve and one section directs air to the scraper relay valve. - Service brake relay valves: Direct air to the brake actuators to engage the service brakes. - Parking brake solenoid valves: Direct air to the brake actuators to release the parking brakes. - Retarder control valve: Directs air to the retarder hydraulic control valve and to the scraper torque converter lockup clutch. - Pressure protection valve: Allows air to flow to the accessory circuits if the system air pressure is at least 520 kPa (75 psi). NOTE: When the engine is running, the parking brakes are engaged by spring force until manually released using the parking brake knob in the cab.
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Text Reference
630G SERIES AIR AND BRAKE SYSTEM PARKING BRAKE RELEASED
SCRAPER
TRACTOR
Brake Actuator
OPERATOR STATION
Brake Actuator
Double Check Valve
Service Brake Control Valve
Pressure Protection Valve
Air Dryer
Retarder Control Valve
Diff. Lock
Air Reservoir
Diff Lock Solenoid Valve
Park Brake Solenoid Valve
Quick Release Valve
Park Brake Solenoid Valve
Air Reservoir
Double Check Valve Retarder
Relay Valve Air Reservoir Brake Actuator
Brake Supply Solenoid Valve
Relay Valve
Brake Actuator
Governor
Retarder Valve Compressor
(637G ONLY)
118
This view shows the air and brake system with the engine running and the parking brakes released. When the parking brake knob in the cab is pushed down, the parking brake switch sends an input signal to the Transmission/Chassis ECM. The ECM sends a corresponding output signal to the parking brake solenoid valves. The solenoid valves open and allow air to flow from the air reservoirs through the double check valves and the quick release and holding valves to the parking brake chamber in the brake actuators. The air fills the parking brake chamber and compresses the parking brake spring which retracts the actuator rod and releases the parking brake. When the operator pulls the park brake knob up, the parking brake switch sends an input signal to the ECM. The ECM sends a corresponding output signal to the parking brake solenoid valves. The solenoid valves close which blocks air flow to the brake actuators. Air is vented from the brake actuator parking brake chambers through the quick release and holding valves and the parking brakes are engaged by spring force.
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Text Reference
630G SERIES AIR AND BRAKE SYSTEM SERVICE BRAKE ENGAGED
SCRAPER
TRACTOR
Brake Actuator
Brake Actuator
OPERATOR STATION
Air Dryer
Retarder Control Valve
Double Check Valve
Service Brake Control Valve
Pressure Protection Valve
Diff. Lock
Air Reservoir
Diff Lock Solenoid Valve
Park Brake Solenoid Valve
Quick Release Valve
Park Brake Solenoid Valve
Air Reservoir
Double Check Valve Retarder
Relay Valve
Brake Supply Solenoid Valve
Relay Valve
Air Reservoir Brake Actuator
Brake Actuator
Governor
Retarder Valve Compressor
(637G ONLY)
119
When the service brake pedal is depressed with the engine running, pilot air is directed from the service brake control valve to the tractor and scraper relay valves. The pilot air opens the relay valves, allowing supply air to flow to the service brake chamber in the brake actuators. Air entering the service brake chamber compresses the service brake spring and moves the actuator rod which engages the service brakes. Air also flows from the brake control valve to the double check valves. The double check valves prevent the parking brake piston and the service brake diaphragm in the brake actuator from being activated at the same time. The service brakes can be used to release the parking brakes. When the service brake pedal is depressed, air flows from the service brake control valve to the tractor double check valve which blocks air from the parking brake circuit. Air then flows to the quick release and holding valve and to the actuator parking brake chamber which releases the tractor parking brakes.
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Text Reference
Air also flows from the service brake control valve to the scraper relay valve. The relay valve opens and directs air to to the double check valve which blocks air from the parking brake circuit. Air then flows to the quick release and holding valve and to the actuator parking brake chamber which releases the scraper parking brakes. When the service brake pedal is released, air flow to the relay valve is blocked at the service brake control valve. The service brake control valve vents the actuator service brake chamber air pressure and the service brakes release.
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Text Reference
120
TIER III G SERIES Operator’s Station The 637G operator’s station has been updated with changes to the instrument panel and the implement control panel.
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Text Reference
1
121
The EMS III Module has a new alert indicator. The indicator (1) turns on if the fuel temperature is to high. The fuel temperature indicator replaced the engine coolant flow indicator. The new ACERT engines no longer monitor coolant flow.
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Text Reference
122
1
2
123
The ejector automatic return mode has two indicator lights in the cab. Indicator (1) is located to the right of the tachometer on the dash. Indicator (2) is located on the panel near the implement control lever. The Transmission/Chassis ECM will put the ejector into automatic return mode when the operator moves the ejector lever to the full right (return) position and then releases it within 1 second. The ejector will stay in the auto return mode until one of the following conditions is met. - The ejector cylinder pressure switch shows high pressure (open) - The ejector has been in return mode for more than 20 seconds - Any ejector solenoid or lever position sensor has an active diagnostic - The operator moves the ejector lever to the left
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1
Text Reference
2
3
4
5
6
124
Several updates have been made to the right operator console. Two alert indicators (1) have been added for the ejector automatic return mode. The throttle lock switch (2) remains in the same general location as Tier II machines. The switch (2) engages the throttle lock to maintain the current engine speed. The power limiter switch (3) reduces scraper engine power when the machine is equipped with an auger. The power limit function will activate only when the auger is engaged. The parking brake switch (4) is used to engage or disengage the parking brake. Push up on the switch (4) to engage the parking brake. All implement controls found on the implement control valve (5) must be in the neutral or off position for two seconds after the machine is started before any implements will be operable.
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Text Reference
The implement controls that affect operation are as follows: - Joystick bowl RAISE/LOWER/QUICK DROP in neutral position - Joystick ejector FORWARD/RETURN/AUTO RETURN in neutral position - Apron lever RAISE/LOWER/HOLD/FLOAT in neutral position - Auger (if equipped) trigger switch in OFF (down) position - Bail (if equipped) trigger switch in the LOWER (down) position - Elevator (if equipped) set speed trigger switch in OFF (down) position If any of the above implement controls are not in the neutral or OFF positions, then none of the implements will be operable until the control is moved to the neutral or OFF position for two seconds. For example, if the machine is started with the bail trigger switch in the RAISE position, none of the implements will be operable until the bail trigger switch is moved to the LOWER position and left there for two seconds. When all of the implement controls have been in the neutral or OFF position for two seconds, the implements will function normally. The hand rest (6) has been added for operator comfort.
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Text Reference
1
125
The mode select switch (1) has been redesigned from the Tier II switch. The mode select switch (1) allows the operator to select from 10 different modes and 46 submodes of operation depending on the machine model. Each Mode or submode selects the functions to be displayed on the numeric readout window.
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Text Reference
126 1 2
127
3 4
Electrical System The jumpstart receptacle (1) and disconnect switch (2) are integrated into a one piece power block for better electrical integrity and serviceability on the tractor. The disconnect switch (2) has a lockable cover which holds the disconnect switch in the off position. All power from the batteries and the jumpstart receptacle (1) are disabled when the disconnect switch (2) is in the off position. The 627G scraper will also have an integrated jumpstart receptacle (3) and disconnect switch (4). Faults will be logged if both disconnects switches are not turned on when either engine is started. The tractor and scraper ECM’s will not communicate until both disconnect switches are turned on.
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Text Reference
TRACTOR ENGINE CONTROL SYSTEM USB SB CAT Date Link
ATA
Fuel Injectors
ECM-A4E4 Service Tool Accessory Timing Calibration Probe
Temperature Coolant Sensor
Top Speed Timing
Inlet Air Temperature Sensor
Bottom Speed Timing
Atmospheric Pressure Sensor
Fuel Temperature Sensor
Turbo Outlet Pressure Sensor Engine Oil Pressure Sensor
CORE Engine Oil Temperature Sensor
Rail Pressure Control Valve Rail Pressure Sensor
CORE 630 ONLY
Throttle Sensor Tractor Ground Level Shutdown Switch
Turbo Inlet Pressure Sensor
Scraper Air Inlet Heater Lamp at Tractor
Throttle Lock Lamp Throttle Lock / Back-up Switch
Start Aid Relay Start Aid Valve
128
Engine Shown is the electronic control system component diagram for the C18 EUI engine. Fuel injection is controlled by the Engine (ECM). Many electronic signals are sent to the Engine ECM by the sensors, the switches, and the senders. The Engine ECM analyzes these signals and sends signals to the various output components. Output components can be relays, lamps, other controls, or solenoids. For example, based on the various input signals, the Engine ECM determines when and for how long to energize the injector solenoids. When the injector solenoids are energized determines the timing of the engine. How long the solenoids are energized determines the injected fuel quantity.
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Text Reference
2
1
129
Fuel injection and other systems are controlled by the Engine ECM (1) located on the left side of the engine. Other systems controlled by the Engine ECM include: - Ether injection - Engine start function - Engine monitoring The Engine ECM has a 120-pin connector and a 70-pin connector. The connectors are identified as "J1" and "J2." Be sure to identify which connector is the J1 or J2 connector before performing diagnostic tests. Occasionally, Caterpillar will make changes to the internal software that controls the performance of the engine. These changes can be performed by using the WinFlash program that is part of the laptop software program Electronic Technician (ET). ET is used to diagnose and program the electronic controls used in Wheel Tractor-Scrapers. A "flash" file must be obtained from Caterpillar and uploaded to the Engine ECM when using the WinFlash program.
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Text Reference
A 2-pin timing calibration connector (2), is located next to the Engine ECM. A timing sensor (magnetic pickup) is installed in the flywheel housing and connected to the timing calibration connector (2), when the engine requires a timing calibration. The timing calibration is performed with ET. Timing calibration improves fuel injection accuracy by correcting for any slight tolerances between the crankshaft, the timing gears, and the timing wheel. Timing calibration is normally performed after the following procedures: - ECM replacement - Cam or crank sensor replacement - Timing wheel replacement
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Text Reference
1 2
3
4
5
130
The turbocharger outlet pressure sensor (1) sends an input signal to the ECM. The ECM compares the value of the turbo outlet pressure sensor with the value of the atmospheric pressure sensor and calculates boost pressure. One function of the turbocharger outlet pressure sensor is to enable the air/fuel ratio control which reduces smoke, emissions, and maintains engine response during acceleration. The system utilizes boost pressure, atmospheric pressure, and engine speed to control the air/fuel ratio. Engine fuel delivery is limited according to boost pressure and engine speed. Intake manifold air temperature (2) is located on the left side of the engine in the head near the air intake. This sensor provides input to the ECM so it can determine the need for derating the engine at high temperature, for engine shutdown at high temperature, and for use by the Machine Monitor System. The cam speed/timing sensor (3) is located on the left side of the engine in the back side of the timing gear housing. This sensor is used as a backup for the crank speed/timing sensor. If the crank speed/timing sensor fails, the cam speed/timing sensor allows for continuous operation.
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Text Reference
The engine oil pressure sensor (4) is located in an adapter on the left side of the engine. Engine oil pressure varies with engine speed. If the engine oil pressure is less than specification, the Engine ECM will log an event. The atmospheric pressure sensor (5) is located in an adapter on the left side of the engine next to the engine oil pressure sensor. The Engine ECM uses the atmospheric pressure sensor as a reference for calculating boost, air filter restriction, and derating the engine at high attitudes. All pressure sensors in the system measure absolute pressure and, therefore, require the atmospheric sensor to calculate gauge pressure. The Engine ECM will derate the engine 10% if the atmospheric pressure sensor fails. The atmospheric pressure sensor is one of the many analog sensors that receive a regulated 5.0 ± 0.5 Volts from the Engine ECM. The atmospheric pressure sensor outputs a variable DC Voltage signal. All the pressure sensor output signals are matched to the atmospheric pressure sensor output signal during calibration. Calibration can be accomplished using the ET service tool or by turning on the key start switch without starting the engine for five seconds.
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Text Reference
1
2
131
The engine coolant temperature sensor (1) is located in the front right of the engine in the thermostat housing. This sensor is used by the Engine ECM to control various functions. The following systems or circuits use the coolant temperature sensor input signal to the Engine ECM: - The Machine Monitor System coolant temperature gauge - Cold mode operation - Automatic ether injection If the jacket water cooling system temperature increases above 107° C (226° F), the Engine ECM will log an event. The engine speed/timing sensor (2) is located on the lower left corner of the engine near the crankshaft output shaft. This sensor measures engine speed and timing for control of the timing and delivery of fuel to each of the engine’s cylinders. Sensing engine speed allows engine speed governing, fuel limiting, and fuel injection timing.
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1
2
Text Reference
3
132
The differential fuel pressure switch (1) is located in the top of the secondary fuel filter housing on the right side of the engine. This switch will indicate restriction in the fuel filter. A warning will be sent by the Engine ECM to the Machine Monitor System. The fuel pressure sensor (2) is located in the top of the secondary fuel filter housing on the right side of the engine. This sensor is used to monitor fuel pressure. The engine fuel temperature sensor (3) is located in the top of the secondary fuel filter housing on the right side of the engine. The Engine ECM uses the fuel temperature measurement to make corrections to the fuel rate and maintain power regardless of fuel temperature (within certain parameters). This feature is called "Fuel Temperature Compensation."
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Text Reference
1
133
The turbocharger inlet pressure sensor (1) is located in a tube between the air cleaners and the turbochargers. The Engine ECM uses the turbocharger inlet pressure sensor in combination with the atmospheric pressure sensor to determine air filter restriction. The Engine ECM provides the input signal to the Machine Monitor System, which informs the operator of the air filter restriction. A level 1 event will be logged if the Engine ECM detects an air filter restriction. A level 2 event will be logged if the Engine ECM derates the engine due to an air filter restriction. INSTRUCTOR NOTE: The Engine ECM will default to max air filter restriction of 14kPA and derate the engine 10% if the turbo inlet or atmospheric pressure sensor fails.
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Text Reference
1
2
134
The ether system is used to improve the cold start capabilities of the engine. Ether is stored in a removable ether bottle (1). The ether solenoid (2) is controlled by the Engine ECM. The Engine ECM uses several sensors and an altitude map to determine when ether should be injected. The Engine ECM monitors the coolant temperature sensor, the air temperature sensor, and the atmospheric temperature sensor to determine the temperature of the machine and the altitude at which the machine is operating. Based on these inputs, the Engine ECM determines when the engine requires ether injection for cold startup. The ether system can be enabled or disabled using Electronic Technician. The 627G may also have an ether starting system on the scraper engine. For more information, refer to REHS2550.
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Text Reference
1
135
The radiator (1) is a Next Generation Modular Radiator (NGMR). The radiator has 3 cores and uses 9 fins per inch.
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Text Reference
1
136
The Air To Air Aftercooler (ATAAC) (1) is located next to the radiator. The ATAAC cools inlet air after the air has been compressed by the turbo charger. The cooled inlet air is then routed to the engine combustion chamber.
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Text Reference
2
137
The air conditioner receiver dryer (2) has changed locations with the updated tractor cooling package. The receiver dryer (2) is now located on the left side of the tractor cooling package.
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Text Reference
1
138
Implement System The implement control valve (1) is located on the right side of the scraper draft tube. The implement control valve (1) functions the same as the previous G Series Wheel Tractor Scraper.
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Text Reference
1
139
The ejector kickout switch (1) is mounted on the right side of the draft frame. The ejector kickout switch (1) signals the Implement ECM to shut off the current to the ejector return solenoid when the ejector reaches the back of the scraper bowl.
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Text Reference
631G / 637G IMPLEMENT HYDRAULIC SYSTEM Eject or Pressure Sensor
Apron Cylinder
HOLD
Bowl Cylinder
Bowl Cylinder
Snubber
Eject or Cylinder Direct ion Valve
RETURN
LOWER
LOWER
Pilot Valve Speed Change Valve From Cushion Hit ch Pump From Implement / St eering Pump
EJECT RAISE RAISE
Pilot Filter
140
This schematic shows the oil flow in the 613G/637G implement hydraulic system in the standard configuration with the engine running and implements in HOLD. In the pilot system, oil from the cushion-hitch pump flows to the pilot solenoid and pressure reducing valve. The pilot solenoid and pressure reducing valve consists of a solenoid valve and a pressure reducing valve. The solenoid valve is controlled by the Implement ECM and controls oil flow from the cushionhitch pump to the pilot system. The pilot solenoid is de-energized during engine start-up, which blocks oil flow to the pilot system. When the engine is running, the pilot solenoid is energized which allows oil to flow from the cushion-hitch pump to the pilot system. The pressure reducing valve limits the pilot system oil pressure to 3450 ± 200 kPa (500 ± 29 psi).
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Text Reference
The implement pump provides oil flow to the implement control valve. When the control valve spools are in the HOLD position, oil flows past the main relief valve and through the opencenter control valves to the tank. The main relief valve opens to the tank when the main system pressure reaches approximately15000 ± 350 kPa (2175 ± 50 psi). In the HOLD position, oil flow to the cylinders and oil flow from the cylinders is blocked at the main control valve spools. NOTE: A relief valve is located between the head end of the apron cylinder and the tank on machines equipped with an auger. The relief valve directs oil from the head end of the apron cylinder to the tank if the apron contacts the apron stop bracket or if the bowl is lowered with the apron against the stop bracket.
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Text Reference
Carry and Quick-drop Valve
631G/637G IMPLEMENT HYDRAULIC SYSTEM Eject or Pressure Sensor
Apron Cylinder
BOWL RAISE
Carry and Quick-drop Valve
Quick-drop Valve
Bowl Cylinder
Quick-drop Valve
Bowl Cylinder
Snubber Carry Valve
Carry Valve
Direct ion Valve
RETURN
LOWER
LOWER
Pilot Valve Speed Change Valve From Cushion Hit ch Pump From Implement / St eering Pump
EJECT RAISE RAISE
Pilot Filter
141
When the implement control lever is moved to the BOWL RAISE position, the control lever position sensor sends a PWM signal to the Transmission/Chassis ECM. The ECM sends a signal to the bowl raise solenoid located on the implement control valve. The bowl raise solenoid drains pilot oil from one side of the bowl spool. The pilot oil on the opposite side of the spool shifts the bowl spool to the Bowl RAISE position. Pump supply oil is directed from the implement control valve to the carry and quick-drop valves. Supply oil flows through a check valve in the carry and quick drop valves and into the rod end of the bowl cylinders. Oil in the rod end of the bowl cylinders retracts the cylinder which raises the bowl. Oil in the head end of the bowl cylinders is forced out of the bowl cylinders and through the carry and quick drop valve to the implement control valve. The implement control valve directs oil back to the hydraulic tank through an open passage. When the implement control lever is released, the bowl control spool returns to the HOLD position. Supply oil is blocked and the bowl stops moving.
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631G / 637G IMPLEMENT HYDRAULIC SYSTEM
Carry and Quick-drop Valve Carry and Quick-drop Valve
BOWL LOWER Eject or Pressure Sensor
Apron Cylinder
Text Reference
Bowl Cylinder
Flow Cont rol
Flow Cont rol
Quick-drop Valve
Quick-drop Valve
Bowl Cylinder
Snubber Carry Valve
Carry Valve
Direct ion Valve
RETURN
LOWER
LOWER
Pilot Valve Speed Change Valve From Cushion Hit ch Pump From Implement / St eering Pump
EJECT RAISE RAISE
Pilot Filter
142
When the implement control lever is moved to the BOWL LOWER position, the control lever position sensor sends a PWM signal to the Transmission/Chassis ECM. The ECM sends a signal to the bowl lower solenoid located on the implement control valve. The bowl lower solenoid drains pilot oil from one side of the bowl spool. The pilot oil on the opposite side of the spool shifts the bowl spool to the BOWL LOWER position. Pump supply oil is directed from the implement control valve to the carry and quick-drop valves. Supply oil flows across the flow control valve and into the head end of the bowl cylinders. Oil in the head end of the bowl cylinders extends the cylinders which lowers the bowl. Oil in the rod end of the bowl cylinders is forced out and flows through the open carry valve. The oil then flows out of the carry and quick drop valve and is directed to the hydraulic tank through a passage in the implement control valve. When the implement control lever is released, the bowl control valve spool returns to the HOLD position, the oil flow is blocked, and the bowl stops moving.
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Carry and Quick-drop Valve
631G / 637G IMPLEMENT HYDRAULIC SYSTEM
Apron Cylinder
Carry and Quick-drop Valve Flow Cont rol
BOWL QUICK-DROP Eject or Pressure Sensor
Text Reference
Quick-drop Valve
Bowl Cylinder
Flow Cont rol
Quick-drop Valve
Bowl Cylinder
Snubber Carry Valve
Carry Valve
Direct ion Valve
RETURN
LOWER
LOWER
Pilot Valve Speed Change Valve From Cushion Hit ch Pump From Implement / St eering Pump
EJECT RAISE RAISE
Pilot Filter
143
When the operator moves the implement control lever to the full forward (detent) position, the QUICK-DROP function is activated. The control lever position sensor sends a PWM signal to the Transmission/Chassis ECM. The ECM sends a signal to the bowl lower solenoid. The bowl lower solenoid drains pilot oil from one side of the bowl spool. The pilot oil on the opposite side of the spool shifts the bowl spool to the QUICK-DROP position. Pump supply oil is directed from the implement control valve to the carry and quick-drop valves. Supply oil flows across the flow control valve and into the head end of the bowl cylinders. Oil in the head end of the bowl cylinders extends the cylinders which lowers the bowl. The oil in the spring chambers of both the carry valve and quick drop valve are open to tank. Oil in the rod end of the bowl cylinders is forced out and flows through the open carry valve. Oil forces the quick drop valve open. Oil flows across the quick drop valve and into the head end of the bowl cylinder as makeup oil. The bowl lowers at a faster rate when in the quick drop mode.
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Text Reference
631G / 637G IMPLEMENT HYDRAULIC SYSTEM Eject or Pressure Sensor
APRON RAISE Bowl Cylinder
Bowl Cylinder
Snubber Apron Cylinder
Auger Relief Valve
Eject or Cylinder
Direct ion Valve
RETURN
LOWER
LOWER
Pilot Valve Speed Change Valve From Cushion Hit ch Pump From Implement / St eering Pump
EJECT RAISE RAISE
Pilot Filter
144
When the thumb lever on the implement control lever is moved to the APRON RAISE position, the thumb lever position sensor sends a PWM signal to the Transmission/Chassis ECM. The ECM sends a corresponding output signal to energize the apron raise solenoid. The apron raise solenoid drains pilot oil from one end of the apron valve spool. The pilot oil on the opposite side of the spool shifts the apron spool to the APRON RAISE position. The apron spool directs oil flow to the head end of the apron cylinder, which raises the apron. Oil from the rod end of the apron cylinder is directed to the hydraulic tank through an open passage in the implement control valve.
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Text Reference
631G/637G IMPLEMENT HYDRAULIC SYSTEM APRON LOWER Eject or Pressure Sensor
Apron Cylinder
Bowl Cylinder
Bowl Cylinder
Snubber
Direct ion Valve
RETURN
LOWER
LOWER
Pilot Valve Speed Change Valve From Cushion Hit ch Pump From Implement / St eering Pump
EJECT RAISE RAISE
Pilot Filter
145
When the thumb lever on the implement control lever is moved to the APRON LOWER position, the thumb lever position sensor sends a PWM signal to the Transmission/Chassis ECM. The ECM sends a corresponding output signal to energize the apron lower solenoid. The apron lower solenoid drains pilot oil from one end of the apron valve spool. The pilot oil on the opposite side of the spool shifts the apron spool to the APRON LOWER position. The apron spool directs oil flow to the rod end of the apron cylinder, which lowers the apron. Oil from the head end of the apron cylinder is directed to the hydraulic tank through an open passage in the implement control valve. When oil pressure in the rod end of the apron cylinder exceeds approximately 16720 ± 172 kPa (2425 ± 25 psi), the relief valve in the apron sequence valve opens. Oil flows from the head end of the apron cylinder to the rod end of the apron cylinder which lifts the apron.
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Text Reference
631G / 637G IMPLEMENT HYDRAULIC SYSTEM APRON FLOAT Eject or Pressure Sensor
Apron Cylinder
Bowl Cylinder
Bowl Cylinder
Snubber
Direct ion Valve
RETURN
LOWER
LOWER
Pilot Valve Speed Change Valve From Cushion Hit ch Pump From Implement / St eering Pump
EJECT RAISE RAISE
Pilot Filter
146
When the thumb lever on the implement control lever is moved to the APRON FLOAT position, the thumb lever position sensor sends a PWM signal to the Transmission/Chassis ECM. The ECM sends a corresponding output signal to energize the apron lower solenoid. The apron lower solenoid drains pilot oil from one end of the apron valve spool. The pilot oil on the opposite side of the spool shifts the apron spool to the APRON FLOAT position. Pump oil is directed to both the rod end of the apron cylinder and the head end of the apron cylinder and to the tank. Since supply oil is also open to the tank, system pressure is reduced to both ends of the cylinder. When the apron is in the APRON FLOAT position, movement of the apron is controlled by gravity and the weight of the apron itself.
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Text Reference
631G/637G IMPLEMENT HYDRAULIC SYSTEM EJECTOR DUMP LOADED Eject or Pressure Sensor
Apron Cylinder
Bowl Cylinder
Bowl Cylinder
Snubber
Eject or Cylinder Direction Valve
LOWER
EJECT
LOWER
Pilot Valve Speed Change Valve From Cushion Hit ch Pump From Implement / St eering Pump
RETURN RAISE RAISE
Pilot Filter
147
When the implement control lever is moved to the EJECT position, the control lever position sensor sends a PWM signal to the Transmission/Chassis ECM. The ECM sends a signal to energize the eject solenoid. The eject solenoid drains pilot oil from one end of the ejector valve spool. The pilot oil on the opposite side of the spool shifts the ejector spool to the EJECT position. Pump supply oil is directed to the speed change valve and to the head end of the ejector cylinder. The oil present at the top of the pilot valve overcomes the force of the pilot valve spring when the oil pressure in the eject circuit is above approximately 12750 kPa (1250 psi). The pilot valve shifts downward and directs supply oil to the spring chamber on the right side of the direction valve. The pressurized oil and the force of the spring will act on the right side of the direction valve and keep it shifted to the left envelope. The direction valve will meter oil from the rod end of the cylinder to the implement control valve. The implement control valve will direct the oil from the rod end of the ejector to the hydraulic tank. When most of the material has been ejected from the scraper bowl, and the system pressure decreases below 12750 kPa (1250 psi) the ejector forward speed will increase.
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Text Reference
631G/637G IMPLEMENT HYDRAULIC SYSTEM EJECTOR DUMP EMPTY Eject or Pressure Sensor
Apron Cylinder
Bowl Cylinder
Bowl Cylinder
Snubber
Eject or Cylinder Direction Valve
LOWER
EJECT
LOWER
Pilot Valve Speed Change Valve From Cushion Hit ch Pump From Implement / St eering Pump
RETURN RAISE RAISE
Pilot Filter
148
When the implement control lever is moved to the EJECT position, the control lever position sensor sends a PWM signal to the Transmission/Chassis ECM. The ECM sends a signal to energize the eject solenoid. The eject solenoid drains pilot oil from one end of the ejector valve spool. The pilot oil on the opposite side of the spool shifts the ejector spool to the EJECT position. Pump supply oil is directed to the speed change valve and to the head end of the ejector cylinder. The oil present at the top of the pilot valve is not enough to overcome the spring force when the oil pressure in the eject circuit is below approximately 12750 kPa (1250 psi). The oil in the spring chamber at the right of the direction valve is connected to tank when the pilot valve is in this position. The pressurized oil on the left of the direction valve overcomes the force of the spring on the right side of the direction valve. The direction valve shifts right and directs oil from the rod end of the ejector cylinder to the head end of the ejector cylinder. Ejector forward speed increases.
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Text Reference
631G / 637G IMPLEMENT HYDRAULIC SYSTEM EJECTOR RETURN Eject or Pressure Sensor
Apron Cylinder
Bowl Cylinder
Bowl Cylinder
Snubber
Eject or Cylinder Direction Valve
LOWER
EJECT
LOWER
Pilot Valve Speed Change Valve From Cushion Hit ch Pump From Implement / St eering Pump
RETURN RAISE RAISE
Pilot Filter
149
When the implement control lever is moved to the RETURN position, the control lever position sensor sends a PWM signal to the Transmission/Chassis ECM. The ECM sends a signal to energize the return solenoid. The return solenoid drains pilot oil from one end of the ejector valve spool. The pilot oil on the opposite side of the spool shifts the ejector spool to the RETURN position. Pump supply oil is directed to the speed change valve. The pump supply oil is metered through an orifice in the direction valve and flows into the rod end of the ejector cylinder. The cylinder will retract and move the ejector toward the rear of the bowl. The oil present at the bottom of the pilot valve is metered through an orifice to the tank. The size of the orifices in the direction valve and the pilot valve determine how fast the ejector will retract. Ejector circuit pressure builds when the ejector is fully retracted. Pressurized oil travels through the snubber and to the ejector pressure switch. At 11700 ± 345 kPa (1697 ± 50 psi) the ejector pressure switch signals the Transmission/Chassis ECM to de-energize the return solenoid when the operator has placed the ejector in the auto return mode.
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Text Reference
150
CONCLUSION This presentation has covered the 637G Wheel Tractor-Scrapers. Component location and basic system operations have been discussed. Refer to the appropriate service manuals for complete and specific information.
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Text Reference
VISUAL LIST 1. Model view (left side) 2. Model views (four machine configurations) 3. Machine features (text) 4. Operator's station 5. Operator's seat 6. Steering column 7. Retarder lever 8. Service brake and governor pedals 9. Implement and transmission control levers 10. Overhead console 11. Instrument panel 12. Left dash indicator display 13. Right dash indicator display 14. Caterpillar Monitoring System 15. Caterpillar Monitoring System components 16. Caterpillar Monitoring System inputs and outputs 17. Gauge cluster module 18. Speedometer/tachometer module 19. Main display module 20. Scraper control panel 21. 637G Scraper Caterpillar Monitoring System components 22. Scraper control panel 23. Diagnostic service connector 24. Service connector 25. 630G Series Electronic Control System 26. Electronic control module locations 27. Electrical center 28. 630G Series Wheel Tractor power distribution 29. 637G Wheel Scraper power distribution and charging subsystem 30. 630G Series Wheel Tractor-Scraper starting/charging/shutdown circuit 31. 630G Series Wheel Tractor starting logic 32. 637G Series Wheel Scraper engine starting logic
33. Batteries and disconnect switches 34. Shutdown switches and auxiliary start receptacles 35. Wiring harness disconnect points 36. 3408E Tractor engine 37. Fuel filters 38. Right side of 3408E engine 39. Left side of 3408E engine 40. Rear of 3408E engine 41. 3408E/3412E HEUI fuel system 42. Engine ECM and HEUI fuel pump 43. HEUI fuel injector 44. 630G Series Tractor Engine Control System 45. C-9 Scraper engine (left side) 46. C-9 engine (right side) 47. Major power train components 48. Tractor power train components 49. Tractor Transmission/Chassis ECM 50. 630G Series Transmission Control System 51. Tractor transmission 52. 630G Series Tractor transmission clutch engagement chart 53. Transmission control lever 54. Tractor transmission oil flow 55. Tractor transmission pump 56. Transmission oil filter 57. Torque converter and transmission lubrication pressure taps 58. Transmission upshift and downshift solenoids 59. Selector and pressure control valve group components 60. Scraper power train components 61. 637G Scraper Transmission Control System 62. Scraper Transmission ECM 63. Scraper transmission components 64. Scraper transfer gear case and differential
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Text Reference
VISUAL LIST 65. 66. 67. 68. 69. 70. 71. 72. 73. 74. 75. 76. 77. 78. 79. 80. 81. 82. 83. 84. 85. 86. 87. 88. 89. 90. 91. 92.
Scraper drive train components Scraper power train oil flow Scraper clutch engagement table Implement hydraulic system block diagram 630G Series Implement Electronic Control System Major implement system components Implement control lever Hydraulic oil tank Implement/steering pump and pump drive 637G implement control valve 637G implement control valve (off machine) Bowl, apron, and ejector Ejector cylinder Ejector speed change valve Bowl and apron components 637G hydraulic system--HOLD 637G hydraulic system--BOWL LOWER 637G hydraulic system--BOWL QUICK-DROP 637G hydraulic system--APRON RAISE 637G hydraulic system--APRON FLOAT 637G hydraulic system--EJECTOR EJECT Cushion-hitch hydraulic system components Cushion-hitch hydraulic system-LOCKDOWN Cushion-hitch hydraulic system-CUSHION RIDE Auger hydraulic system components Auger hydraulic system--AUGER OFF Auger hydraulic system--AUGER ON 637G push-pull hydraulic system components
93. 637G push-pull hydraulic system--BAIL LOWER 94. 637G push-pull hydraulic system--BAIL RAISE 95. Steering hydraulic system block diagram 96. Steering system major components 97. Steering main hydraulic system components 98. Steering pilot hydraulic system components and secondary steering pump 99. Steering hydraulic system--HOLD 100. Steering hydraulic system--LEFT TURN 101. Steering hydraulic system with secondary steering--HOLD 102. Air and brake system block diagram 103. Tractor Transmission ECM inputs and outputs 104. Air compressor 105. Air dryer 106. Air reservoirs 107. Air reservoir drain valves 108. Air system pressure sensors 109. Air and brake system components in cab 110. Brake actuators 111. Service brake components 112. Parking/secondary brake components 113. Retarder circuit components 114. Retarder pressure switch 115. Pressure protection valve 116. Differential lock circuit components 117. Air and brake system schematic--Engine running 118. Air and brake system schematic-PARKING BRAKES RELEASED 119. Air and brake system schematic-SERVICE BRAKES ENGAGED 120. Operator’s station 121. EMS III module 122. Auto ejector return indicator (dash) 123. Auto ejector return indicator (console)
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VISUAL LIST 124. 125. 126. 127. 128. 129. 130. 131. 132. 133. 134. 135. 136. 137. 138. 139. 140. 141. 142. 143. 144. 145. 146. 147. 148. 149. 150.
Right operator’s console Instrument cluster Tractor power block Scraper power block Engine ECM block diagram Engine ECM Engine sensors Engine sensors Fuel sensors Turbocharger inlet pressure switch Ether starting system Next Generation Modular Radiator (NGMR) Air to air aftercooler (ATAAC) Air conditioner receiver dryer Implement control valve Ejector kickout switch Hydraulic system--HOLD Hydraulic system--BOWL RAISE Hydraulic system--BOWL LOWER Hydraulic system--BOWL QUICK DROP Hydraulic system--APRON RAISE Hydraulic system--APRON LOWER Hydraulic system--APRON FLOAT Hydraulic system--EJECTOR DUMP LOADED Hydraulic system--EJECTOR DUMP EMPTY Hydraulic system--EJECTOR RETURN Rear of machine
Text Reference
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Handout No. 1
Lab A: Display and List Modes of Operation Worksheet No. 1 Directions: Using the operator mode switch, display the operator modes on the Caterpillar Monitoring System Main Display Module and record the information shown in the Display Area of the Main Display Module on Worksheet No. 1. Using the 4C8195 Control Service Tool, display the service modes on the Caterpillar Monitoring System Main Display Module and record the information shown in the Display Area of the Main Display Module on Worksheet No. 2.
OPERATOR MODES (631G) Mode 1: Display: Mode 2: Display:
Mode 3: Display:
Mode 4: Display:
Mode 5: Display: Mode 6: Display: Mode 7: Display: Mode 8: Display:
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Lab A: Display and List Modes of Operation Worksheet No. 1 (continued) OPERATOR MODES (637G) Mode 1: Display:
Mode 2: Display:
Mode 3: Display:
Mode 4: Display:
Mode 5: Display:
Mode 6: Display:
Mode 7: Display:
Mode 8: Display:
Handout No. 2
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Lab A: Display and List Modes of Operation Worksheet No. 1 continued) Mode 9: Display:
Mode 10: Display:
Handout No. 3
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Lab A: Display and List Modes of Operation Worksheet No. 1 continued) SCRAPER OPERATOR MODES (637G) Mode 1: Display:
Mode 2: Display:
Mode 3: Display:
Mode 4: Display:
Mode 5: Display:
Mode 6: Display:
Handout No. 4
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Lab A: Display and List Modes of Operation Worksheet No. 2 SERVICE MODES Mode 1: Display:
Mode 2: Display:
Mode 3: Display:
Mode 4: Display:
Handout No. 5
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Handout No. 6
Lab B: Electronic Control System Parameters Worksheet
Directions: Connect the ET Service Tool to the class machine. Click the start button on the computer tool bar to establish communication between the ET Service Tool and the ECMs. Display the machine parameters and record the parameter information on the Lab B Worksheets. TRACTOR ENGINE PARAMETERS Description
Value
Unit
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Handout No. 7
Lab B: Electronic Control System Parameters Worksheet (continued)
TRACTOR TRANSMISSION PARAMETERS Description
Value
Unit
SCRAPER TRANSMISSION PARAMETERS Description
Value
Unit
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Handout No. 8
Lab B: Electronic Control System Parameters Worksheet (continued)
IMPLEMENT SYSTEM PARAMETERS Description
Value
Unit
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Handout No. 9
LAB C: WHEEL TRACTOR POWER TRAIN HYDRAULIC SYSTEM TESTS 630G SERIES WTS WHEEL TRACTOR TRANSMISSION VISUAL AND OPERATIONAL TESTS
Machine Model
Date
Machine Serial Number
Machine Hours
VISUAL CHECKS Oil level - transmission?
Oil level - differential?
Oil leaks?
Hose damage?
Air/Water in oil?
Magnetic Screen debris?
Batteries charged?
Oil filter debris?
Condition of Fuses/Harnesses/Connectors? Diagnostic Codes?
OPERATIONAL CHECKS Check 1: Rotary Actuator and Spool - rotates through all gear positions? Check 2: Downshift Solenoid - clicking or buzzing noise occurs? Check 3: Upshift Solenoid - clicking or buzzing noise occurs? Check 4: Engine Speed - engine RPM
tachometer reading (RPM)
Check 5: Differential Lock - when ENGAGED, full steering available? - when DISENGAGED, full steering available? Check 6: Retarder (if equipped) - engine RPM with retarder ENGAGED Check 7: Transmission Shifting - does the transmission shift correctly? Check 8: (Optional Check) - any damage present on final drive covers? - are the backlash measurements for the bevel gear, pinion and differential correct?
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Handout No. 10
LAB C: WHEEL TRACTOR POWER TRAIN HYDRAULIC SYSTEM TESTS
630G SERIES WTS WHEEL TRACTOR TRANSMISSION TESTS TEST TRANSMISSION PUMP PRESSURE (kPa or PSI) RETARDER OPERATION TEST (RPM)
STATUS SPECIFICATION High Idle Low Idle Engine RPM
LUBRICATION OIL PRESSURE (kPa or PSI)
Low Idle Neutral High Idle Neutral Retarder ON/H.I. Retarder OFF/H.I
TORQUE CONVERTER OUTLET PRESSURE (kPa or PSI)
High Idle 2nd Speed
PILOT PRESSURE (kPa or PSI)
Low Idle Neutral
Transmission Oil Temperature - C ( F)
(during tests)
ACTUAL
ADJUSTED VALUE
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Handout No. 11
LAB C: WHEEL TRACTOR POWER TRAIN HYDRAULIC SYSTEM TESTS 630G WTS CLUTCH CHART SPEED CLUTCHES ENGAGED
PRIMARY CLUTCH PRESSURE Load Piston Plug Removed STATION CLUTCH
N
4
A
1
R
1 and 7
B
2
1
1 and 6
C
7
2
1 and 5
E
5
3
3 and 6
F
4
4
2 and 6
G
6
5
3 and 5
H
3
6
2 and 5
7
3 and 4
8
2 and 4
630G WTS CLUTCH CHART
A
1
B
2
C
7
E
5
F
4
G
6
H
3
ACTUAL
MAXIMUM CLUTCH PRESSURE Load Piston Plug Installed SPECS
STATION CLUTCH
SPECS
LOW IDLE
HIGH IDLE
ACTUAL LOW IDLE
HIGH IDLE
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Handout No. 12
Lab D: 637G Wheel Scraper Power Train Hydraulic System Tests
SCRAPER TRANSMISSION HYDRAULIC SYSTEM TESTS SPECIFICATION
TEST TRANSMISSION PUMP PRESSURE (kPa or PSI) RETARDER OPERATION TEST (RPM)
ACTUAL
ADJUSTED VALUE
High Idle Low Idle Engine RPM High Idle
LUBRICATION OIL PRESSURE (kPa or PSI)
TORQUE CONVERTER OUTLET PRESSURE (Engine RPM) and (kPa or PSI) SPEED CLUTCH PRESSURE (P1) (kPa or PSI)
DIRECTIONAL CLUTCH PRESSURE (P2) (kPa or PSI)
Low Idle Retarder ON Retarder OFF High RPM Stall RPM T.C Outlet Lube Low Idle Neutral Low Idle In Gear High Idle In Gear Low Idle Neutral Low Idle In Gear High Idle In Gear
If the speed clutch (P1) and load clutch (P2) pressures are too high, what problems may have occurred?
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Handout No. 13
Lab D: 637G Wheel Scraper Power Train Hydraulic System Tests
637G
If the synchronizing valve pressures are too low with the synchronizing solenoid harness disconnected, what problems may have occurred?
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Handout No. 14
Lab E: Implement Hydraulic System Operational Tests Worksheet No. 1 Machine Model_____________________________ Date____________________________ Serial Number______________________________ S.M.H.__________________________ VISUAL CHECKS Oil level______________
Oil Viscosity_____________ Oil leaks?__________________
Air/Water in Oil?_____
Suction Screen Debris?______Oil Filter Examination________
TEST Bowl Drift Bowl Lift Time Apron Drift Apron Lift Time Ejector Cycle Time - Rear to Forward Ejector Cycle Time - Forward to Rear
SPECS
ACTUAL
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Handout No. 15
Lab E: Implement Hydraulic System Testing and Adjusting Worksheet No. 2 Machine Model_____________________________ Date___________________________ Serial Number______________________________ S.M.H.________________________ VISUAL CHECKS Oil level____________
Oil Viscosity______________
Oil leaks?______________
Air/Water in Oil?_____
Suction Screen Debris?______
Oil Filter Examination_____
TEST Main Relief Valve Pressure Cushion-Hitch Pressure Compensator Valve Pilot Pressure Reducing Valve Apron Sequence Valve Pressure
SPECS
ACTUAL
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Handout No. 16
Lab F: Implement System Calibrations Worksheet Directions: Multiple Choice. Circle the correct letter indicating the best answer for each question. 1.
When performing the initial calibrations after ECM replacement the ____________ calibrations should be performed first. A. B. C. D.
2.
During the implement control lever calibrations the implement ECM determines the full range of motion for the implement control lever. These values are then stored in the ________________. A. B. C. D.
3.
Implement ECM Calibrations Implement Control Lever Calibrations CAT Monitoring System Calibrations Implement Solenoid Calibrations
Tractor Transmission ECM Implement ECM CAT Monitoring System Electronic Technician
When the ejector solenoid is replaced, the ______________ calibration (s) must be performed. A. B. C. D.
Implement Control Lever Calibration Only Ejector, and Bowl Solenoids Calibrations Ejector Solenoids Calibration Only Ejector Solenoids and Implement Control Lever Calibrations
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Handout No. 17
Lab G: Cushion-Hitch System Testing and Adjusting Worksheet
CUSHION-HITCH TESTS Test
Pressure Compensator Valve
Leveling Valve Linkage
Accumulator Test and Charge
Specifications
Actual
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Handout No. 18
Lab H: Elevator Hydraulic System Testing and Adjusting Worksheet
Machine Model________________________
Date__________________________
Serial Number_________________________
S.M.H.________________________
VISUAL CHECKS: Oil level____________
Oil leaks?____________
Air/water in Oil?__________
Oil Filter Examination______________________________________________________
ELEVATOR OPERATIONAL TESTS TEST
SPECIFICATIONS
ACTUAL
Elevator Speed Elevator Chain Tension
Elevator Chain Length
PRESSURE TESTS TEST Cushion-Hitch Pressure Compensator Valve
Pilot Pressure Reducing Valve Elevator Pump Discharge Pressure
SPECIFICATIONS
ACTUAL
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Handout No. 19
Lab I: Auger Hydraulic System Testing and Adjusting Worksheet
Machine Model__________________________
Date__________________________
Serial Number___________________________
S.M.H.________________________
VISUAL CHECKS: Oil level_____________
Oil leaks?____________
Air/water in Oil?__________
Oil Filter Examination______________________________________________________
AUGER OPERATIONAL TEST TEST
SPECIFICATIONS
ACTUAL
Auger rpm
PRESSURE TESTS TEST Pressure Override (POR) Valve Pressure at High Idle Pump Crossover Relief Valve Pressure at High Idle Motor Crossover Relief Valve Pressure at High Idle Charge Pressure at High Idle Motor Shift Point
SPECIFICATIONS
ACTUAL
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Handout No. 20
Lab J: Push-Pull Hydraulic System Testing and Adjusting Worksheet
Machine Model__________________________
Date__________________________
Serial Number___________________________
S.M.H.________________________
VISUAL CHECKS: Oil level_____________
Oil leaks?____________
Air/water in Oil?__________
Oil Filter Examination______________________________________________________
PRESSURE TESTS
TEST Bail Cylinder Cycle Time Cushion-Hitch Pressure Compensator Valve Push-Pull Relief Valve (Bail RAISE) Push-Pull Relief Valve (Bail LOWER)
SPECIFICATIONS
ACTUAL
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Handout No. 21
Lab K: Steering System Performance Checks Worksheet Machine Model___________________________
Date____________________________
Serial Number____________________________
S.M.H.__________________________
VISUAL CHECKS Oil level____________
Oil Viscosity_____________ Oil leaks?__________________
Air/Water in Oil?_____
Suction Screen Debris?_____ Oil Filter Examination________
TEST Steering Wheel Free Play Check Steering Wheel Force Check Steering Wheel Slip Check Steering Time Check
SPECS
ACTUAL
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Handout No. 22
Lab L: Steering System Testing and Adjusting Worksheet
Machine Model__________________________
Date__________________________
Serial Number___________________________
S.M.H.________________________
VISUAL CHECKS: Oil level_____________
Oil leaks?____________
Air/water in Oil?__________
Oil Filter Examination______________________________________________________
TESTS
TEST Pressure Reducing Valve Steering Cylinder Crossover Relief Valve
Steering Cylinder Pressure Steering System Pressure
SPECIFICATIONS
ACTUAL
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Handout No. 23
Lab M: Air System and Brakes Operational Checks Worksheet
Machine Model__________________________
Date__________________________
Serial Number___________________________
S.M.H.________________________
VISUAL CHECKS: Damaged Components___________ Line Restrictions__________ Crack/Worn Hoses________ Loose Connections__________
Air Leaks__________
OPERATIONAL CHECKS Directions: Perform the following operational checks: _____Parking and Secondary Brake Check _____Differential Lock Check _____Quick Release Holding Valve Check _____Caterpillar Monitoring System Panel Check Specifications
Actual
_____Retarder Control Valve Check (Tractor)
_______
______
_____Retarder Control Valve Check (Scraper)
_______
______
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Handout No. 24
Lab N: Air System and Brakes Testing and Adjusting Worksheet
Machine Model__________________________
Date__________________________
Serial Number___________________________
S.M.H.________________________
VISUAL CHECKS: Damaged Components_________
Line Restrictions__________ Crack/Worn Hoses________
Loose Connections_________
Air Leaks__________
TEST/ADJUST Air Pressure Gauge Air Compressor Governor Parking Brake Control Parking Brake Solenoid Valve Circuit Parking Brake Solenoid Resistance Retarder Control Valve Retarder Air Control Regulator Service Brake Adjustment
SPECIFICATIONS
ACTUAL
