tm1691 Service ADVISOR™ 8
tm1691 Service ADVISOR™ (1) 9
Safety Features 11
Recognize Safety Information 12
Follow Safety Instructions 13
Operate Only If Qualified 14
Wear Protective Equipment 15
Avoid Unauthorized Machine Modifications 16
Inspect Machine 17
Stay Clear of Moving Parts 18
Avoid High-Pressure Fluids 19
Beware of Exhaust Fumes 20
Prevent Fires 21
Prevent Battery Explosions 23
Handle Chemical Products Safely 24
Dispose of Waste Properly 25
Prepare for Emergencies 26
Use Steps and Handholds Correctly 27
Start Only From Operator’s Seat 28
Use and Maintain Seat Belt 29
Prevent Unintended Machine Movement 30
Avoid Work Site Hazards 31
Keep Riders Off Machine 32
Avoid Backover Accidents 33
Avoid Machine Tipover 34
Add and Operate Attachments Safely 35
Use Special Care When Operating 36
Operating or Traveling On Public Roads 37
Inspect and Maintain ROPS 38
Stay Clear of Rotating Drivelines 39
Park and Prepare for Service Safely 42
Service Cooling System Safely 44
Remove Paint Before Welding or Heating 45
Make Welding Repairs Safely 46
Drive Metal Pins Safely 47
Safety Sign 48
General Information 50
POWERTECH 4.5L (4045) and 6.8L (6068) John Deere Engines 83
Engine—Sectional View 84
General Engine Description 86
POWERTECH 4.5L (4045) and 6.8L (6068) John Deere Engines (1) 87
Make Visual Inspection of Engine and Supporting Systems 88
Diagnose Engine Malfunctions 90
POWERTECH 4.5L (4045) and 6.8L (6068) John Deere Engines (2) 105
JT05801 Clamp-On Electronic Tachometer Installation 106
Adjust Engine Speed Control Linkage (S.N. 872335—882699) 107
Adjust Engine Speed Control Linkage (S.N. 882700— ) 112
Adjust Slow and Fast Idle (S.N. —882699) 114
POWERTECH 4.5L (4045) and 6.8L (6068) John Deere Engines (3) 116
Air Intake System Leakage Test 117
Altitude Compensator Boost Pressure Engine Performance Test 119
Injection Pump Timing (S.N. —882699) 122
Injection Pump Timing (S.N. 882700— ) 124
Fuel Line Leakage Test 125
Electrical Diagram Information 126
Component Identification Table 133
Fuse (Blade-Type) Color Codes 135
Fuse Location and Specifications (S.N. —880053) 136
Wiring and Schematic Diagrams Legend (S.N. —880053) 138
System Functional Schematic Section Legend (S.N. —880053) 141
System Functional Schematic (S.N. —880053) 142
Fuse Location and Specifications (S.N. 880054—882699) 144
Wiring and Schematic Diagrams Legend (S.N. 880054—882699) 146
System Functional Schematic Section Legend (S.N. 880054—882699) 149
System Functional Schematic (S.N. 880054—882699) 150
Fuse Location and Specifications (S.N. 882700— ) 153
Wiring and Schematic Diagrams Legend (S.N. 882700— ) 156
System Functional Schematic Section Legend (S.N. 882700— ) 161
System Functional Schematic (S.N. 882700— ) 162
Main Harness (W4) Component Location (S.N. —880053) 165
Main Harness (W4) Connectors, Wire and Pin Location (S.N. —880053) 166
Main Harness (W4) Component Location (S.N. 880054—882699) 167
Main Harness (W4) Connectors, Diode, Wire and Pin Location (S.N. 880054—882699) 169
Main Harness (W4) Component Location (S.N. 882700— ) 175
Main Harness (W4) Connectors, Diode, Wire and Pin Location (S.N. 882700— ) 177
Transmission Diode Harness (W5) Component Location (S.N. —880053) 180
Transmission Diode Harness (W5) Component Location (S.N. 880054— ) 181
Differential Lock, Park Brake and MFWD Solenoid Diode Harness (W6) Component
Location (S.N. —880053) 182
Differential Lock, Park Brake and MFWD Solenoid Diode Harness (W6) Component
Location (S.N. 880054— ) 183
ROPS Harness (W7) Component Location (S.N. —880053) 184
ROPS Harness (W7) Component Location (S.N. 880054— ) 185
Dash Harness (W8) Component Location (S.N. —880053) 186
Dash Harness (W8) Connector, Wire and Pin Location (S.N. —880053) 188
Dash Harness (W8) Component Location (S.N. 880054—882699) 190
Dash Harness (W8) Connector, Wire, and Pin Location (S.N. 880054—882699) 192
Dash Harness (W8) Component Location (S.N. 882700— ) 197
Dash Harness (W8) Connector, Wire, and Pin Location (S.N. 882700— ) 199
Engine Harness (W9) Component Location (S.N. 882700— ) 204
Engine Harness (W9) Connector, Wire, and Pin Location (S.N. 882700— ) 206
Power Shift Transmission Harness (W10) Component Location 209
Power Shift Transmission Harness (W10) Connector, Wire, and Pin Location 211
12-Volt Power Outlet Harness (W11) Component Location—Optional (S.N. 882700— ) 215
Power Circuit Operational Information (S.N. —880053) 217
Power Circuit Theory of Operation (S.N. —880053) 218
Power Circuit Schematic (S.N. —880053) 219
Power Circuit Operational Information (S.N. 880054— ) 220
Power Circuit Theory of Operation (S.N. 880054— ) 221
Power Circuit Schematic (S.N. 880054— ) 222
Power Circuit Sub-System Diagnostics 223
Start Circuit Operational Information 240
Start Circuit Theory of Operation (S.N. —880053) 241
Start Circuit Schematic (S.N. —880053) 242
Start Circuit Theory of Operation (S.N. 880054— ) 243
Start Circuit Schematic (S.N. 880054— ) 244
Start Circuit Sub-System Diagnostics 245
Charging Circuit Operational Information 259
Charging Circuit Theory of Operation 260
Charging Circuit Schematic (S.N. —880053) 261
Charging Circuit Schematic (S.N. 880054— ) 262
Charging Circuit Sub-System Diagnostics 263
PTO Circuit Operational Information—If Equipped 273
PTO Circuit Theory of Operation—If Equipped 274
PTO Circuit Schematic—If Equipped 275
PTO Circuit Sub-System Diagnostics—If Equipped 276
Display Monitor and Warning Indicator Switches Circuit Specifications 281
Display Monitor and Warning Indicator Switches Circuit Operational Information 282
Display Monitor and Warning Indicator Switches Circuit Theory of Operation (S. N.
—880053) 283
Display Monitor and Warning Indicator Switches Circuit Schematic (S.N. —880053) 285
Display Monitor and Warning Indicator Switches Circuit Theory of Operation (S.N.
880054—882699) 286
Display Monitor and Warning Indicator Switches Circuit Schematic (S.N.
880054—882699) 289
Display Monitor and Warning Indicator Switches Circuit Theory of Operation (S. N.
882700— ) 290
Display Monitor and Warning Indicator Switches Circuit Schematic (S.N. 882700— ) 294
Display Monitor and Warning Indicator Switches Circuit Sub-System Diagnostics 295
Neutral Disconnect Circuit Specifications—Manual Shift 318
Neutral Disconnect Circuit Operational Information—Manual Shift 319
Neutral Disconnect Circuit Theory of Operation—Manual Shift 320
Neutral Disconnect Circuit Schematic—Manual Shift (S.N. —880053) 323
Neutral Disconnect Circuit Schematic—Manual Shift (S.N. 880054— ) 324
Neutral Disconnect Circuit Sub-System Diagnostics—Manual Shift 325
Range Shift Circuit Theory Of Operation—Power Shift 351
Range Shift Circuit Schematic—Power Shift 354
Range Shift Circuit Sub-System Diagnostics—Power Shift 355
Engine Control Unit Circuit Theory of Operation and Circuit Schematic (S.N. 882700— ) 373
Alternators and Starting Motors 375
Access Engine Diagnostic Trouble Codes Using Blink Method (S.N. 882700— ) 376
Engine Diagnostic Trouble Codes (S.N. 882700— ) 379
Throttle Position Sensor Test (S.N. 882700— ) 386
Engine Coolant Temperature Sensor Test 389
Battery Operation 390
Battery Specifications 391
Diagnose Battery Malfunctions 392
Check Battery Electrolyte Level And Terminals 393
Using Booster Batteries—12 Volt System 397
Alternator Operation—65 Amp Bosch 399
Forward, Reverse, Low Range Forward and Third Speed Clutch Pack Operation 401
Power Shift High Range Forward, First Speed and Second Speed Clutch Packs 403
Manual Shift Power Train Overview 405
Torque Converter Operation 407
Manual Shift Synchronizer Operation 409
Transmission Pump Operation 411
Transmission Filter Operation 413
Manual Shift Transmission Operation—First Gear Forward 414
Manual Shift Transmission Operation—Third Gear Reverse 416
Power Shift Power Train Overview 418
Power Shift Transmission Gear Flow 420
Mechanical Front Wheel Drive (MFWD) Operation 422
Manual Shift Transmission Control Valve Operation 424
Manual Shift Transmission Control Circuit—Neutral with Park Brake Off 426
Manual Shift Transmission Control Circuit—Forward 429
Manual Shift Transmission Control Circuit—Reverse 431
Power Shift Transmission Clutch Engagement And Solenoids Activated 433
Power Shift Transmission Control Circuit—Neutral With Park Brake Off 435
Power Shift Transmission Control Valve and Shift Valve Operation—Neutral 438
Power Shift Transmission Control Circuit—First Forward 440
Power Shift Transmission Control Valve and Shift Valve—First Forward 443
Power Shift Transmission Control Circuit—High Range (Fourth) Forward 445
Power Shift Transmission Control Valve and Shift Valve—High Range (Fourth) Forward 448
Power Shift Transmission Control Circuit—First Reverse 450
Power Shift Transmission Control Valve and Shift Valve—First Reverse 453
Manual Shift Modulation Valve Operation 455
Power Shift Modulation Valve Operation 457
Differential Operation 460
Differential Lock Operation 462
Brake Valve Operation (S.N. —880907) 464
Brake Valve Operation—General Information (S.N. 880908— ) 466
Brake Valve Operation—Neutral, Engine Operating (S.N. 880908— ) 467
Brake Valve Operation—One Pedal Applied, Engine Operating (S.N. 880908— ) 470
Brake Valve Operation—Both Pedals Applied, Engine Operating (S.N. 880908— ) 473
Brake Valve Operation—Both Pedals Applied, Engine Stopped (S.N. 880908— ) 476
Service Brake Operation 478
Park Brake Operation 480
MFWD Differential Operation—Unequal Traction (If Equipped) 482
MFWD Differential Operation—Equal Traction (If Equipped) 484
Diagnose Power Train Malfunction 485
Diagnose MFWD Malfunction—If Equipped 504
Diagnose Rear Axle Malfunction 505
Hydraulic Circuit Symbols 512
Adjust Brake Pedals and Equalizing Valves (S.N. —880907) 513
Adjust Brake Pedals (S.N. 880908— ) 517
Bleed Service Brakes (S.N. —880907) 519
Bleed Service Brakes (S.N. 880908— ) 521
Tracking Angle Check and Adjust—MFWD Axle 524
Toe-In Check and Adjust 526
Steering Angle Check and Adjust—MFWD Axle 530
Transmission Oil Warm-Up Procedure 532
Manual Shift Transmission Overall Test Connections, Ports, and Locations 535
Power Shift Transmission Overall Test Connections, Ports, and Locations 537
Torque Converter Stall Speed Test 539
Converter-In Relief Valve Test 542
Brake Valve Leakage Test 545
Park Brake Release Pressure Test 548
Transmission System Pressure Test 551
Manual Shift Forward and Reverse Clutch Pressure Test 554
Power Shift Low Range Forward, High Range Forward, Reverse and Speed Clutch
Pressure Test 558
Reducing Valve Pressure Test 561
Modulation Valve Pressure Test 564
Differential Lock Pressure Test 568
MFWD Pressure Test—If Equipped 571
Transmission Cooler In and Cooler Out Pressure Test 574
Solenoid Circuit Leakage Test 578
Transmission Pump Flow Test 579
Open-Center Hydraulic System 582
Hydraulic System Component Location (S.N. —872334) 584
Hydraulic System Component Location (S.N. 872335—880907) 586
Hydraulic System Component Location (S.N. 880908–882034) 588
Hydraulic System Component Location (S.N. 882035—882699) 590
Hydraulic System Component Location (S.N. 882700—883904) 592
Hydraulic System Component Location (S.N. 883905— ) 594
Hydraulic System Schematic (S.N. —883904) 597
Hydraulic System Schematic (S.N. 883905— ) 598
Hydraulic Control Valve Component Locations (S.N.883905— ) 600
Hydraulic Pump Operation 602
Hydraulic Filter Operation 603
Steering Valve Operation 605
Priority Valve Operation (S.N. —883904) 613
Priority Valve Section Operation —Steering Actuated (S.N. 883905— ) 619
Relief Valve Operation With Anticavitation (S.N. 883905— ) 621
Relief Valve Without Anticavitation (S.N. 883905— ) 623
Outlet Plate (S.N. —883904) 624
Control Valve—Bucket Section (S.N. —883904) 625
Control Valve—Boom Section—Raise (S.N. —883904) 627
Control Valve—Boom Section—Lower (S.N. —883904) 629
Control Valve—Boom Section—Float (S.N. —883904) 631
Control Valve—Flow Control Section (S.N. —883904) 633
Control Valve—Hitch Lift Section (S.N. —883904) 635
Control Valve—Hitch Pitch Section (S.N. —883904) 637
Control Valve—Hitch Tilt and Auxiliary Sections (S.N. —883904) 639
Control Valve—Inlet Section with System Relief Valve (S.N. 883905— ) 641
Control Valve—Bucket Section—Dump (S.N. 883905— ) 643
Control Valve—Boom Section—Raise (S.N. 883905— ) 645
Control Valve—Flow Control Section (S.N. 883905— ) 647
Control Valve—Boom Section—Float (S.N. 883905— ) 649
Control Valve—Hitch Pitch Section (S.N. 883905— ) 651
Control Valve—Hitch Lift Section—Raise (S.N. 883905— ) 653
Control Valve—Hitch Tilt and Auxiliary Sections (S.N. 883905— ) 655
Use These Seven Basic Steps to Diagnose and Test the Hydraulic System 657
Make a Pretest Inspection and an Operation Check of the Machine 658
Hydraulic System Pretest 659
Diagnose Hydraulic System Problems 660
Loader Bucket Self-Leveling Linkage Indicator Adjustment (S.N. —870948) 674
Loader Bucket Self-Leveling Linkage Indicator Adjustment (S.N. 870949— ) 678
Return-to-Dig Switch Adjustment 681
JT05800 Digital Thermometer Installation 685
Hydraulic Oil Warm-Up Procedure 686
Hydraulic Pump Flow Test (S.N. —880053) 687
Hydraulic Pump Flow Test (S.N. 880054—883904) 689
Hydraulic Pump Flow Test (S.N. 883905— ) 692
Priority Relief Valve Pressure Test (S.N. —888053) 695
Priority Relief Valve Pressure Test (S.N. 880054—883904 ) 698
Priority Relief Valve Pressure Test (S.N. 883905— ) 701
System Relief Valve Pressure Test (S.N. —883904) 703
System Relief Valve Pressure Test (S.N. 883905— ) 705
Hydraulic Oil Cooler Restriction Test (S.N. —883904) 707
Hydraulic Oil Cooler Restriction Test (S.N. 883905— ) 710
Circuit Relief Valve Test—With Remote Pump (S.N. —883904) 713
Circuit Relief Valve Test—With Remote Pump (S.N. 883905— ) 716
Steering System Leakage Test 719
Steering Cylinder Leakage Test 723
Hydraulic Cylinder Drift Test Procedure 725
Function Drift Test 726
Cylinder Leakage Test 729
Cycle Time Specifications (S.N. —883904) 731
Cycle Time Specifications (S.N. 883905— ) 733
Hydrostatic PTO System Component Location (S.N. —882699) 735
Hydrostatic PTO System Component Location (S.N. 882700—) 737
Hydrostatic PTO System Schematic—If Equipped 739
Hydrostatic PTO Pump Operation—If Equipped 740
Hydrostatic PTO Pump Control Circuit Operation—Actuated 742
Hydrostatic PTO High Pressure Relief Valve Operation 745
Hydrostatic PTO Motor Operation—If Equipped 747
Diagnose Hydrostatic PTO System Problems 749
Before Performing Hydrostatic PTO Tests and Adjustments 753
Hydrostatic PTO Pump Servo Piston Neutral Adjustment—If Equipped 754
Before Performing Hydrostatic PTO Tests and Adjustments (1) 757
Hydrostatic PTO Pump Neutral Charge Relief Valve Pressure Test and Adjustment—If
Equipped 758
Hydrostatic PTO Pump High Pressure Relief Valve and Pressure Override Valve Tests
and Adjustments—If Equipped 762
PTO Oil Cooler Restriction Test (S.N. —882699) 770
PTO Oil Cooler Restriction Test (S.N. 882700—) 773







