Part of the John Deere Repair Manuals.
Testing hydrostatic charge pressure on a JD855 means putting a gauge on the system and comparing the reading to 260 to 340 psi in neutral and 180 to 240 psi while operating. TM-1165 gives you those specs, the 6300 to 6700 psi relief valve test and the circuit fold outs that show where the oil goes.
This is the Jun-84 edition of TM-1165, with repair, operation and test in one book. It covers the turbocharged, intercooled 619 cu. in. six, the transfer drive, brakes, loader cylinders and the three spool loader valve. There is also a Steel Mill Loader spec page.
Diagnosis in this book is done with gauges, a flow meter and the seven step operational checkout. The pages print cleanly as a working copy for the shop.
What's Inside This John Deere JD855 Manual
| System | Pages | Key Topics |
|---|---|---|
| General Information | 1-88 | Sectional Contents and Index, General Specifications, Crawler Loader and Steel Mill Loader Variants, Fuels, Lubricants, Periodic Service |
| Tracks | 89-180 | Track Systems, Specifications and Special Tools |
| Axles and Suspension Systems | 181-212 | Drive Axle Housing and Support, Axle Shaft, Bearings and Reduction Gears |
| Transmission | 213-392 | Controls, Input Drive Shafts and U-Joints, Hydrostatic Transmission Hydraulic System, Clutch Disconnect and Controls |
| Engine | 393-554 | Removal and Installation, Crankshaft and Main Bearings, Camshaft, Pistons and Rods, Cylinder Head and Valves, Fuel Injection, Turbocharger, Water Pump, Starting Motor, Flywheel |
| Engine Auxiliary Systems | 555-580 | Cold Weather Starting Aids, Cooling Systems, Speed Controls, Intake, External Exhaust and Fuel Supply |
| Transfer Drive | 581-594 | Housings and Covers, Gears, Shafts and Bearings |
| Parking-Emergency and Service Brakes | 595-610 | Active Elements, Controls Linkage, Brake Hydraulic System |
| Equipment Attaching | 611-616 | Drawbar, Towbar |
| Electrical Systems | 617-680 | Batteries and Cables, Alternator and Regulator, Lighting, Wiring Harness and Switches, System Controls, Instruments and Indicators |
| Frames | 681-686 | Frame Installation, Bottom Guards, Chassis Weights |
| Operator's Station | 687-738 | Operator Enclosure, Heating and Air Conditioning |
| Sheet Metal, Safety and Miscellaneous | 739-758 | Hood and Engine Enclosure, Shields, Grille, Fenders, Fire Extinguisher, Horn |
| Loader | 759-814 | Buckets, Controls Linkage, Loader Frames, Loader Hydraulic System and Cylinder Repair |
| PTO or Winch Drive and Ground Conditioning Tool | 815-822 | Winch Drive Housing and Covers, Ripper Controls Linkage and Hydraulic System |
| System Testing - Operational Checkout and Engine | 823-856 | Seven Step Operational Checkout for the Hydrostatic Crawler, Engine Diagnosis |
| System Testing - Electrical System | 857-886 | Circuit Tests, Complete Electrical Schematic and Wiring Diagram Fold Outs |
| System Testing - Power Train and Loader Hydraulics | 887-938 | Power Train Diagnosis, Hydraulic System Flow Meter Tests, Loader Hydraulic Schematic |
| System Testing - Hydrostatic System | 939-1094 | Charge Pressure and High Pressure Relief Tests, Theory of Operation, Test Procedures, Circuit Diagram Fold Outs |
| System Testing - Miscellaneous, Specifications and Special Tools | 1095-1142 | Miscellaneous Components, Heating and Air Conditioning, Test Specifications, Special Tools |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| Engine | John Deere 6-cylinder turbocharged and intercooled diesel | p. 43 |
| Gross power @ 1800 rpm (SAE) | 220 hp (164 kW) | p. 43 |
| Net power @ 1800 rpm (SAE / DIN) | 200 hp (149 kW) / 203 PS | p. 43 |
| Bore and stroke | 5.12 x 5 in. (130 x 127 mm) | p. 43 |
| Piston displacement | 619 cu. in. (10 147 cm3) | p. 43 |
| Maximum torque @ 1300 rpm | 730 lb-ft (990 N·m) | p. 43 |
| Electrical system | 24 volt with alternator | p. 43 |
| Travel speed | 0 to 6.5 mph (0 to 10.5 km/h) forward or reverse | p. 43 |
| Loader hydraulic pump | Vane, 70 gpm (4.42 L/s) at rated engine speed | p. 43 |
| Loader hydraulic pressure | 2600 psi (174 bar) | p. 43 |
| SAE operating weight | 49,600 lb. (22 499 kg) | p. 44 |
| Track shoes / gauge | 39 per side, 18 in. (457 mm) grouser, 76 in. (1.93 m) gauge | p. 44 |
| Ground pressure | 12.4 psi (0.85 bar) | p. 44 |
| Fuel tank | 106 gal. (401.2 L) | p. 44 |
| Cooling system | 10.5 gal. (39.8 L) | p. 44 |
| Crankcase including filters | 36.5 qt. (34.5 L) | p. 44 |
| Hydrostatic drives / loader hydraulic system | 46 gal. (174.1 L) / 40 gal. (151.4 L) | p. 44 |
| Hydrostatic neutral charge pressure | 260 to 340 psi (18 to 23 bar) | p. 943 |
| Hydrostatic operating charge pressure | 180 to 240 psi (12 to 17 bar) | p. 943 |
| Forward and reverse relief valve setting | 6300 to 6700 psi (434 to 461 bar) | p. 944 |
John Deere JD855 Common Problems This Manual Covers
Track comes off, or roller flanges and chain rails are chipping
The manual says a track that is too loose chips the roller flanges and chain rails, or comes off completely. The Tracks section covers the track system, track specifications and special tools. Use it to set tension correctly before replacing rollers or rails.
Manual Section: Tracks p. 838Hydrostatic charge pressure or relief setting is out of spec
Run the seven step operational checkout first, then go to System Testing - Hydrostatic System. Test charge pressure against 260 to 340 psi in neutral and 180 to 240 psi operating. Check forward and reverse relief at 6300 to 6700 psi, using the circuit fold outs to trace the flow.
Manual Section: System Testing - Hydrostatic System p. 943Oil leaking from power train housings
The power train diagnosis lists the usual causes in order. Check cap screw torque, look for a cracked housing, then look for a failed gasket and worn or missing seals and O-rings. System Testing - Power Train and Loader Hydraulics walks through the checks. The Transfer Drive section covers the housings and covers you may need to remove.
Manual Section: System Testing - Power Train and Loader Hydraulics p. 895Loader hose fittings keep working loose or weeping
A twisted hose straightens out under pressure and loosens its own connection, so the manual says to install hoses without twists. To find pressure side leaks, inspect the components, fittings and hoses. Then run the loader hydraulic system flow meter tests in System Testing to confirm pump and relief valve condition.
Manual Section: Loader - Loader Hydraulic System; System Testing - Power Train and Loader Hydraulics p. 768Frequently Asked Questions
Does the JD855 TM-1165 cover testing the hydrostatic drive, or only teardown?
It covers both. The System Testing - Hydrostatic System section has theory of operation, test procedures and circuit diagram fold outs. It also covers the charge pressure and high pressure relief tests. Neutral charge pressure is 260 to 340 psi, operating is 180 to 240 psi, and forward and reverse relief is 6300 to 6700 psi. p. 943
My JD855 lacks power or smokes. Where does the manual start?
Start with the engine diagnosis in System Testing - Operational Checkout and Engine. It sends you to valve clearance, timing, a dirty air intake, overheating and the fuel system. The Engine section then covers the cylinder head and valves, fuel injection and the turbocharger. For reference, rated net power is 200 hp at 1800 rpm. p. 845
Is there a full wiring diagram for the JD855 24 volt system?
Yes. System Testing - Electrical System includes a complete electrical schematic and a wiring diagram with wire numbers, both as fold outs. It also has circuit tests. The Electrical Systems section covers batteries and cables, the alternator and regulator, lighting, switches, instruments and indicators. p. 861
Can I reseal the JD855 loader cylinders with this book?
Yes. The Loader section takes you through cylinder repair with the repair kits. You remove the rod guide, pull the piston and rod, then replace the seals. The same section covers buckets, the controls linkage and loader frames. A loader hydraulic schematic for the three spool loader valve is in the testing chapters. p. 790
What oil and fill capacities does the JD855 manual list?
The book recommends John Deere TORQ-GARD SUPREME engine oil. The crankcase takes 36.5 qt. with filters. The hydrostatic drives take 46 gal. and the loader hydraulic system takes 40 gal. Hydraulic oil should sit halfway up the level window. Fuel is 106 gal. and cooling is 10.5 gal. p. 44
