1992 John Deere 750B / 850B Crawler Dozer Operation and Test Technical Manual (P/N TM1332)

John Deere technical publication TM1332 (20MAY92) covers operation, testing, and system diagnosis for the 1992 750B and 850B crawler dozers, including standard, long track, low ground pressure (LGP), hydraulic, angle, and bulldozer configurations.

Searchable Text, Bookmarks and Foldout Diagrams

Text search and diagram detail: The main text is searchable, with embedded bookmarks for sections and individual tests. Search does not cover all diagram labels or the hydrostatic diagnostic flowcharts. Small labels on some wiring diagrams and foldout schematics require zooming.

One printable PDF in English contains 643 pages, including two cover pages and 40 blank or header-only pages.

Crawler Checkout, Hydrostatic Tests and System Diagnosis

Beyond these selected topics, the manual includes fuel shut-off cable adjustment and front-idler horizontal and vertical adjustment.

• Operational checkout: OK/NOT OK checks of machine functions, controls, driving behavior, safety interlocks, and cab equipment.

• Engine diagnosis: Cooling, air, lubrication, and fuel-system checks, injection-pump timing, fuel-system bleeding, and engine performance tests.

• Hydrostatic drive: Control-circuit bleeding, pump and motor phasing, tracking adjustments, transmission volumetric efficiency testing, and charge-pressure fault isolation.

• Blade hydraulics: System and circuit relief-valve tests, cylinder drift and seal-leakage checks, pump-flow measurements, and cycle-time tests.

• Power train and tracks: Cold-weather disconnect clutch, splitter drive, final drives, park brakes, and sealed versus lubricated track-chain measurements.

• Electrical troubleshooting: Starting, charging, indicator, lighting, and accessory circuit tests, with wiring diagrams and connector and ground-location drawings.

• Heating and air conditioning: R-12 system operation, refrigerant recovery and charging procedures, compressor-oil service, and pressure-switch and expansion-valve tests.

Written for experienced technicians, this manual identifies the essential tools and test equipment required for the work.

Operational Checkout and Engine Tests

Structured check-and-verify sequences support shop-floor performance checks, with results pointing to the next diagnostic group. Engine sectional views accompany the operating theory; test procedures cover valve lift, compression, fuel-transfer pressure, and lubricating-oil pressure.

Repair scope: Complete machine repair information is in separate manual TM1476. Additional engine information requires CTM4 for 6414 engines, CTM8 for 6068 engines, CTM1 for 6466 engines, and CTM11 for engine accessories; these publications are not included.

Hydrostatic Fault Isolation and Tracking

Step-by-step procedures cover synchronization of the injection pump and transmission control valve, initial start-up after transmission repair, and transmission control-circuit bleeding. C-, S-, and J-pattern tracking charts link the direction and speed of mistracking to specific adjustments, helping technicians choose the next check before changing settings.

Diagnostic flowcharts address no movement, lack of power or cycling, neutral complaints, overheating, and mistracking. The later single-charge-pump system uses pressure-side filtration, and the manual excludes that configuration from the earlier inlet-vacuum check.

Excessive force on the FNR handle can damage the valve's lever stops, a specific caution in the full-speed control-pressure adjustment section.

Blade Hydraulics and Undercarriage

Relief-pressure tests are separated from cylinder-leakage and pump-performance checks. Drawings include Blade Lift Cylinder Bypass Valve and Angledozer Tilt Cylinder Bypass Valve views.

Undercarriage data distinguish sealed and lubricated track chains, with wear limits for rollers, bushings, links, and front idlers. Torque tables cover track-shoe hardware, metric and inch bolts, O-ring boss fittings, and flange connections.

Secure the machine before diagnostic work and follow the manual's pressure-relief precautions before opening hydraulic lines.

Electrical Circuits and R-12 Air Conditioning

Model- and serial-specific drawings include the 750B Starting Circuit, 850B with Cab Charging Circuit, and hydrostatic Hydraulic Schematics for the two principal serial groups.

The charging section warns that switching the battery disconnect off with the engine running can load-dump the alternator and damage the charging system.

HVAC procedures extend to evacuation and leak testing, supported by an Operating Pressure Diagnostic Chart for the documented R-12 system.

Compression-Test and Cold-Weather Oil Examples

For the 750B at normal engine operating temperature, the compression-test specifications include a minimum of 350 psi and a maximum difference of 50 psi between cylinders.

The engine-oil notes reduce the oil-and-filter interval to 125 hours when the listed API CC or military alternatives are used in SAE 5W20, SAE 5W30, or Arctic grades.