John Deere 777, 797 Max-Frame ZTrak Mowers Technical Manual TM2077 01FEB06 PDF

Table of Contents
Specifications ……………………………………………9
Vehicle Specifications ………………………………9
Repair Information……………………………………12
Metric Fastener Torque Values………………..12
Metric Fastener Torque Values – Grade 7….13
Inch Fastener Torque Values…………………..14
Hydraulic Fitting Service Recommendations15
O-Ring Seal Service Recommendations……18
Gasoline…………………………………………………..19
Using Proper Fuel ………………………………….19
Oils & Lubricants……………………………………..19
Engine Oil …………………………………………….19
Hydrostatic Transmission and Hydraulic Oil.20
Grease………………………………………………….20
Alternative Lubricants……………………………..20
Synthetic Lubricants ……………………………….21
Lubricant Storage…………………………………..21
Mixing of Lubricants ……………………………….21
Oil Filters ………………………………………………21
Coolant Specifications……………………………..21
Gasoline Engine Coolant…………………………21
Gasoline Engine Coolant Drain Interval …….22
Machine Identification………………………………22
Identification Number Locations……………….22
Engine
Table of Contents
Specifications ………………………………………….25
General Specifications ……………………………25
Tests and Adjustments Specifications……….26
Repair Specifications………………………………26
Torque Specifications……………………………..28
Tools and Materials ………………………………….30
Tools…………………………………………………….30
Theory of Operation …………………………………31
Cooling System Operation ………………………31
Ignition System Operation……………………….32
Fuel Supply and Air Intake System
Operation………………………………………………32
Carburetor Operation – Model 777 ……………33
Fuel Injection Components and Operation –
Model 797……………………………………………..35
Fuel Pressure Regulator Operation –
Model 797……………………………………………..36
Crankcase Breather Operation…………………37
Governor Operation………………………………..37
Automatic Compression Release (ACR)
Operation………………………………………………38
Lubrication System Operation………………….39
Diagnostics ……………………………………………..40
Engine Diagnosis …………………………………..40
Tests and Adjustments …………………………….46
Test Spark …………………………………………….46
Adjust Throttle Lever ………………………………46
Adjust Throttle Cable………………………………47
Adjust Choke – Model 777 ……………………….47
Adjust Governor …………………………………….48
Adjust Slow Idle Speed …………………………..48
Adjust Fast Idle Speed ……………………………49
Check Compression……………………………….49
Check and Adjust Valve Clearance ………….50
Test Crankcase Vacuum …………………………51
Test Engine Oil Pressure ………………………..52
Test Fuel Flow – Model 777……………………..53
Test Fuel Flow – Model 797……………………..54
Test Fuel Pressure – Model 777……………….55
Test Fuel Pressure – Model 797……………….55
Adjust Fan Belt Tension ………………………….56
Radiator Bubble Test………………………………57
Pressure Test Radiator Cap…………………….57
Test Thermostat …………………………………….57
Test Cooling System……………………………… 58
Repair…………………………………………………….. 59
Remove and Install Rear Grille –
S.N. ( -030000) …………………………………….. 59
Remove and Install Rear Grille –
S.N. (030001- ) …………………………………….. 59
Servicing Cooling System………………………. 59
Remove and Install Thermostat………………. 61
Remove and Install Fan Belt…………………… 61
Remove and Install Cooling Fan and
Bracket………………………………………………… 62
Remove and Install Coolant Pump ………….. 63
Remove and Install Radiator …………………. 65
Remove and Install Muffler…………………….. 67
Remove and Install Air Cleaner –
S.N. ( -030000) …………………………………….. 67
Remove and Install Air Cleaner –
S.N. (030001- ) …………………………………….. 68
Remove and Install Fuel Pump –
Model 777……………………………………………. 69
Remove and Install Fuel Pump –
Model 797……………………………………………. 70
Remove and Install Throttle Cable ………….. 70
Remove and Install Choke Cable –
Model 777……………………………………………. 71
Remove and Install Carburetor –
Model 777……………………………………………. 71
Remove Throttle Body – Model 797…………. 74
Remove and Install Fuel Injector –
Model 797……………………………………………. 75
Remove and Install Fuel Pressure
Regulator – Model 797 …………………………… 76
Bleed Fuel System – Model 797………………. 77
Remove and Install Intake Manifold –
Model 777……………………………………………. 77
Remove and Install Intake Manifold –
Model 797……………………………………………. 78
Push Rod and Rocker Arm
Removal and Installation ……………………….. 80
Remove and Install Cylinder Head ………….. 82
Disassemble and Assemble Cylinder
Head and Valves ………………………………….. 84
Inspect Cylinder Head and Valves…………… 84
Analyze Valves …………………………………….. 87
Recondition Valve Seats………………………… 88
Lap Valves…………………………………………… 89
Remove and Install Engine…………………….. 89
Remove and Install Ignition Coil ……………… 90
Electrical
Table of Contents
Specifications ………………………………………..121
Test and Adjustment Specifications ………..121
Repair Specifications…………………………….122
Theory and Diagnostic Information …………123
Theory of Operation Information …………….123
Diagnostic Information…………………………..123
Wire Color Abbreviation Chart………………..123
Electrical Schematic Information …………….124
Reading Electrical Schematics……………….124
Schematic and Wiring Harness Legend …..125
Component ID Legend ………………………….125
Component Location………………………………128
Electrical Components – Model 777 ………..128
Electrical Components – Model 797 ………..130
Schematics and Harnesses …………………….132
Electrical Schematic – Model 777 –
S.N. ( -020000) (1 of 4) …………………………132
Electrical Schematic – Model 777 –
S.N. (020001- ) (1 of 4) …………………………136
Electrical Schematic – Model 797 –
S.N. ( -020000) (1 of 5) …………………………140
Electrical Schematic – Model 797 –
S.N. (020001- ) (1 of 5) …………………………145
W1 – Main Wiring Harness …………………….150
W2 – Engine Wiring Harness ………………….168
W3 – PTO Clutch Wiring Harness……………172
W4 – Optional Headlight Wiring Harness….172
Circuit Operation and Diagnosis……………..173
Power Circuit Operation –
Unswitched Power………………………………..173
Power Circuit Operation – Switched Power,
Standard Equipment……………………………..173
Power Circuit Diagnosis ………………………..178
Cranking Circuit Operation …………………….186
Cranking Circuit Diagnosis …………………….189
Run Circuit Operation – Operator On Seat –
Model 777……………………………………………193
Run Circuit Operation – Operator Off Seat –
Model 777……………………………………………198
Run Circuit Operation – Operator On Seat –
Model 797……………………………………………203
Run Circuit Operation – Operator Off Seat –
Model 797……………………………………………210
Run Circuit Diagnosis – Model 777………….218
Run Circuit Diagnosis – Model 797 ………… 223
Charge Circuit Operation……………………… 232
Charge Circuit Diagnosis……………………… 234
PTO Clutch Circuit Operation ……………….. 237
PTO Clutch Circuit Diagnosis ……………….. 240
Hour Meter Circuit Operation………………… 244
Hour Meter Circuit Diagnosis………………… 246
Engine Oil Pressure Warning Light
Circuit Operation…………………………………. 248
Engine Oil Pressure Warning Light
Circuit Diagnosis…………………………………. 250
Engine Coolant Temperature Light
Circuit Operation…………………………………. 253
Engine Coolant Temperature Light
Circuit Diagnosis…………………………………. 255
ECU Sensors and Diagnostic Circuit
Operation…………………………………………… 258
ECU Sensors Circuit Diagnosis…………….. 262
Optional Headlight Circuit Operation ……… 267
Optional Headlight Circuit Diagnosis ……… 268
Tests and Adjustments …………………………. 270
Common Circuit Tests …………………………. 270
Ground Circuit Test……………………………… 270
Start Circuit Check………………………………. 271
Battery Test ……………………………………….. 272
Charge Battery……………………………………. 273
Battery Load Test ……………………………….. 273
Regulated Voltage Output Test …………….. 274
Unregulated Voltage Output Test ………….. 275
Stator Test …………………………………………. 275
Starting Motor Solenoid Test ………………… 276
Fuse Test…………………………………………… 276
Diode Test …………………………………………. 277
Relay Test………………………………………….. 277
Key Switch Test………………………………….. 278
Control Lever Switch Test and
Adjustment…………………………………………. 278
Brake Switch Test……………………………….. 279
PTO Switch Test…………………………………. 280
Seat Switch Test –
S.N. (010001-020000) …………………………. 280
Seat Switch Test – S.N. (020001- ) ………… 281
Ignition Coil Test…………………………………. 281
Engine Oil Pressure Switch Test …………… 282
Fuel Shutoff Solenoid Test – Model 777 …. 283
Optional Headlight Switch Test……………… 283
Engine Coolant Temperature Switch Test . 284
Fuel Injector Test – Model 797………………. 284
Specifications ………………………………………..295
General Specifications ………………………….295
Adjustment Specifications ……………………..295
Test Specifications ……………………………….295
Repair Specifications…………………………….295
Other Materials…………………………………….296
Special or Essential Tools……………………..296
Component Location………………………………297
Hydraulic System Hose Routing……………..297
Theory of Operation ……………………………….298
JIC Hydraulic Circuit Symbols………………..298
Power Train Operation ………………………….300
Hydraulic System Schematic………………….301
Diagnostics ……………………………………………302
Hydrostatic System Diagnosis………………..302
Tests and Adjustments …………………………..308
Bleed Hydraulic System ………………………..308
Checking and Adjusting Motion Control
Linkages……………………………………………..308
Check and Adjust Control Damper Neutral 310
Checking and Aligning Motion Control
Levers…………………………………………………311
Check and Adjust Neutral Lock Effort ……..312
Test Hydrostatic Pump Flow ………………….313
Repair…………………………………………………….315
Inspect and Replace Pump Drive Belt –
S.N. (010001-020000)…………………………..315
Inspect and Replace Pump Drive Belt –
S.N. (020001- )…………………………………….316
Repair Control Linkage………………………….318
Repair Hydrostatic Pump Drive Belt Tensioner
Assembly – S.N. (010001-020000) ………….320
Remove and Install Control Damper ……….321
Remove and Install Hydrostatic Pump …….321
Disassemble and Inspect Hydrostatic
Pump………………………………………………….324
Assemble Hydrostatic Pump ………………….329
Remove and Install Wheel Motor ……………334
Disassemble and Assemble Wheel Motor..335
Wheel Motor Assembly …………………………340
Specifications ………………………………………..347
General Specifications ………………………….347
Adjustment Specifications ……………………..347
Repair Specifications…………………………….347
Component Location and Operation ……….348
Brake System Operation ……………………….348
Diagnostics ……………………………………………349
Park Brake…………………………………………..349
Tests and Adjustments …………………………..351
Check and Adjust Park Brake ……………….351
Repair…………………………………………………….353
Remove and Install Brake Band……………..353
Remove and Install Wheel Hub………………354
Repair Park Brake Linkage ……………………355
Attachments
Table of Contents
Specifications ………………………………………..359
General Specifications ………………………….359
Repair Specifications…………………………….359
Special or Essential Tools……………………..359
Recommended Blades for 60-Inch
Mulch-On-Demand Deck……………………….360
Theory of Operation ……………………………….361
PTO Clutch Operation …………………………..361
Diagnostics ……………………………………………362
Mower Drive Checks …………………………….362
Mower Drive Checks (Engine Running) …..363
Poor Mulching – Mulch-On-Demand Deck..364
Operational Problems……………………………364
PTO Clutch Diagnostics ………………………..367
Tests and Adjustments …………………………..369
Leveling Mower Deck……………………………369
Adjusting Deck Lift Spring Tension …………371
Adjusting Mower Deck Gauge Wheels…….371
Adjusting Mulch-On-Demand Mower Deck
Linkage (Optional)………………………………..372
Check and Adjust PTO Clutch Air Gap ……373
Adjust Primary Belt Tension –
MCS Blower ………………………………………..374
Adjust Secondary Belt Tension –
MCS Blower ………………………………………..374
Adjust Dump From Seat Hopper Linkage…374
Repair…………………………………………………….376
Remove and Install Mower Deck
Assembly…………………………………………….376
Replace Mower Deck Drive Belt …………….377
Replace Mule Drive Belt………………………..378
Check and Adjust Mule Drive Belt Tension380
Disassemble and Inspect Mule Drive Belt
Idler and Tensioner Assembly………………..382
Inspect and Replace Mower Blades………..383
Sharpen Blades……………………………………384
Balance Blades ……………………………………384
Remove and Install Spindle Assembly…….385
Disassemble and Inspect Spindle …………..386
Spindle Cross Section …………………………..387
Assemble Spindle…………………………………388
Remove and Install Jacksheave Assembly389
Mower Deck Lift Linkage ……………………….391
Gauge Wheels……………………………………..392
Mulch-on-Demand Deck Linkage ………….. 393
Idlers and Sheaves……………………………… 395
Repair (Optional Vertical MCS)………………. 397
Removing Drive Belt……………………………. 397
Installing Drive Belt……………………………… 397
Blower Assembly Disassemble and
Assemble…………………………………………… 398
Repair (Optional Horizontal MCS) ………….. 401
Remove and Install Secondary Drive Belt . 401
Remove and Install Primary Drive Belt…… 401
Disassemble Blower Assembly …………….. 402
Assemble Blower……………………………….. 404
Specifications ………………………………………..409
Repair Specifications…………………………….409
Special or Essential Tools……………………..409
Repair…………………………………………………….410
Remove and Install Control Console
Cover………………………………………………….410
Remove and Install Fuel Tank ……………….410
Remove and Install Seat Platform…………..411
Repair Seat Platform …………………………….411
Replace Lower Seat Cushion…………………412
Seat Latch Repair…………………………………412
Remove and Install Height-of-Cut (HOC)
Assembly…………………………………………….412
Height-of-Cut (HOC) Detent Effort
Adjustment ………………………………………….413
Lubricate Height-of-Cut Ball Detent…………414
Remove and Install Front Caster Wheels…414
Repair Caster Wheel …………………………….414
Caster Wheel Yoke Assembly Removal
and Installation …………………………………….415
Adjust Front Caster Shimmy ………………….415
Remove and Install Rear Drive Wheels …..416
Remove and Install ROPS …………………….416
Seat Latch Repair S.N. (030001- ) ………….417