Part of the John Deere Repair Manuals.
This is the Operation and Test technical manual for John Deere 8120, 8220, 8320, 8420 and 8520 row-crop tractors. It is the diagnostic book: service codes for the ACU, CCU, PCU and ECU controllers, observable symptom charts, system operational checks, electrical schematics and pressure test specs with the actual numbers - standby 30-40 bar, stall 196-210 bar, pilot 19-22 bar at the PS port. Coverage runs from engine, fuel/air and cooling through the powershift transmission, hydraulics, steering/brakes, operator station and the AMS side: GreenStar, AutoTrac, JDLink and Field Doc. This is the manual you open when the tractor throws a code or something quits, before you touch a wrench.
What's Inside This Manual
| System | Pages | Key Topics |
|---|---|---|
| General | 5-79 | Safety, Standard Torque Charts, Diagnostic Tools |
| Service Codes | 80-841 | Acu, Ccu, Pcu and ECU Code Lists, Code Readout on Corner Post Display, Code Diagnostics |
| Observable Symptoms | 842-1072 | Symptom-To-Section Charts for Engine, Hitch, Hydraulics, Transmission, AutoTrac |
| System Diagnosis | 1073-1172 | Cross-System Diagnostic Sequences, Hydraulic and Electrical System Entry Points |
| Engine | 1173-1198 | Operational Checks, Oil and Coolant Pressure Tests, Viscous Fan Drive Checks, Sensor Resistance Tables |
| Fuel and Air | 1199-1214 | Fuel Filter Ratings, Air Cleaner and Precleaner Checks, Fuel System Theory |
| Electrical | 1215-1434 | Wiring Diagrams, Component Location, Circuit Tests, Harness and Connector Diagnostics |
| Control Units | 1435-2132 | Acu, Ccu, Pcu, ECU and Icu References, Calibration Procedures, Controller Schematics |
| Ams GreenStar | 2133-2174 | GreenStar Display Setup, Diagnostics and Schematics |
| Ams JDLink | 2175-2224 | JDLink Telematics Diagnostics, Modem and Connectivity Checks |
| Ams AutoTrac | 2225-2452 | AutoTrac Steering Diagnostics, Ssu Tests, Activation and Calibration |
| Ams Field DOC | 2453-2587 | Field DOC Documentation Setup, Controller Diagnostics |
| Powershift Transmission | 2588-2692 | Operational Checks, Clutch Pressure Tests, Park Brake Leak Test, Transmission Schematics |
| Drive Systems | 2693-2734 | MFWD and Final Drive Checks, Differential Lock Operation and Tests |
| Steering and Brakes | 2735-2809 | Steering Pressure Tests, Brake Operational Checks, Valve Adjustments |
| Hydraulic System | 2810-2995 | Standby, Pilot and Stall Pressure Tests, SCV and Hitch Tests, Hydraulic Schematics |
| Operator Station | 2996-3180 | Cab, HVAC, Seat and Armrest Controls, Display Diagnostics |
| Tools | 3181-3213 | Special and Service Tools Required for the Tests in This Manual |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| Hydraulic Oil Cooler Differential Pressure (38°C (100°F)) | 340-480 kPa (3.4-4.8 bar) (50-70 psi) | p. 2825 |
| Hydraulic Oil Cooler Differential Pressure (65°C (150°F)) | 138-278 kPa (1.3-2.8 bar) (20-40 psi) | p. 2825 |
| Pilot Pressure (PS port) | 1900-2200 kPa (19-22 bar) (275-320 psi) | p. 2825 |
| Standby Pressure (P port) | 3000-4000 kPa (30-40 bar) (435-580 psi) | p. 2825 |
| Stall Pressure (P port) | 19600-21000 kPa (196-210 bar) (2850-3050 psi) | p. 2825 |
| Typical Lube Pressure (38°C (100°F) at 1000 rpm) | 120 kPa (1.2 bar) (17 psi) | p. 2825 |
| Typical Lube Pressure (38°C (100°F) at 2000 rpm (minimum pressure)) | 410 kPa (4.1 bar) (60 psi) | p. 2825 |
| Coolant Temperature Sensor Resistance at RH Console 21 °C (70 °F) | 3065 Ohms | p. 1180 |
| Coolant Temperature Sensor Resistance at RH Console 60 °C (140 °F) | 570 Ohms | p. 1180 |
| Coolant Temperature Sensor Resistance at RH Console 82 °C (180 °F) | 318 Ohms | p. 1180 |
| Coolant Temperature Sensor Resistance at RH Console 100 °C (212 °F) | 178 Ohms | p. 1180 |
| Radiator Pressure | 80 kPa (0.8 bar) (12 psi) | p. 1182 |
| Radiator Cap Pressure | 60-80 kPa (0.6-0.8 bar) (9-12 psi) | p. 1182 |
| Engine Oil Pressure - Minimum No Load (Idle) | 138 kPa (1.38 bar) (20 psi) | p. 1182 |
