2010 John Deere 444J, 544J, 624J Wheel Loader Operation and Tests Manual (TM2135)

John Deere technical publication TM2135, issued July 2010, covers operation and testing for the 444J, 544J, and 624J wheel loaders within the serial-number ranges listed above. The separate Loader Repair Manual contains the main component disassembly and overhaul procedures.

• Operational checkout: Whole-machine checks for starting, shifting, brakes, steering, loader controls, and optional equipment, with directions to the relevant diagnostic sections.

• Engine testing: Engine-speed checks, air intake leakage testing, and engine power assessment using turbocharger boost pressure, supported by model-specific ECU fault references.

• Electrical diagnosis and repair: System functional schematics, wiring diagrams, DTC references, connector terminal repairs, and controller removal and installation.

• Power train and brakes: Electronic transmission clutch calibration, pressure testing, differential and axle troubleshooting, and service-brake and park-brake checks.

• Hydraulics and steering: Pump-flow and valve-leakage tests, pilot-control adjustments, brake accumulator precharge testing, and secondary-steering diagnosis.

• Heating and A/C: System operation, symptom-based troubleshooting, refrigerant leak testing, and temperature/pressure charts for the covered loader configurations.

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

Engine and Fuel-System Diagnostics

POWERTECH engine coverage distinguishes the Level 12 electronic fuel system with a DE10 pump on the 444J and 544J from the Level 11 Denso HPCR system on the 624J. ECU circuit descriptions explain sensor inputs, injection control, and protective fuel derating.

The engine power test lists the JT07248 Manifold Pressure Test Gauge Kit and model-specific boost specifications. Detailed base-engine and fuel-system service is referenced to separate component manuals; the DE10 injection-pump timing entry directs the reader to those separate instructions.

Electrical Fault Tracing and Controller Replacement

CAN Monitor Unit (CMU), Flex Load Controller (FLC), Sealed Switch Module (SSM), Vehicle Electrical Center (VEC), and Transmission Control Unit (TCU) information connects electronic commands with machine functions. DTC charts identify relevant fuses, wire colors, connectors, and circuit references.

The Starting and Charging Circuit and Load Center Harness (W3) Wiring Diagrams accompany component-location drawings, connector end views, electrical symbols, and switch continuity charts. Serial-specific electrical sections help technicians select the correct wiring layout before tracing a fault.

Connector repairs include CINCH terminal service with the JDG1725 extractor. Controller replacement instructions cover CMU programming and electronic controller reconfiguration; reconfiguration resets enabled options and requires the machine configuration to be restored.

Transmission, Axles, and Hydraulic Controls

Transmission information explains clutch modulation and calibration. The pump-flow test warns that starting the engine with the flow-meter loading valve closed can damage the transmission pump.

Differential Lock Operation section views distinguish earlier and later 444J arrangements. Axle disconnect checks address front-wheel drive engagement; additional TEAMMATE III inboard planetary axle information is referenced to a separate component manual.

Hydraulic System Schematics support diagnosis of return-to-dig, return-to-carry, boom height kickout, ride control, pin disconnect, and proportional and reversing fan functions. Boom and bucket cycle-time checks distinguish Z-Bar and Tool Carrier configurations.

The service brake accumulator has a dedicated precharge test but is serviced as a complete unit. Prolonged secondary-steering pump operation with the steering in neutral can damage the pump and motor.

Use the specified boom supports and articulation lock, and follow the pressure-release precautions for the particular procedure; some tests require the engine to remain running.

Cab Heating and Refrigerant-System Tests

The Refrigerant System Cycle of Operation drawing explains the cooling circuit, while the Operating Pressure Diagnostic Chart links gauge patterns to possible faults. The A/C test provides separate temperature/pressure charts for the 444J/544J and 624J.

Examples of Intake and Boost Test Specifications

These figures are a small selection of the manual's test specifications.

For the covered models, the air intake leakage test specifies a pressure of 13.8–20.7 kPa (2–3 psi).

Under the specified engine-loading test, with engine coolant and transmission oil at 72–92°C (160–200°F), turbocharger boost is 62–83 kPa for the 444J and 544J, and 83–103 kPa for the 624J. This test serves as a guide to engine condition.

PDF Navigation, Readability, and Included Pages

Search and page quality: The PDF has no searchable text layer or embedded bookmarks. Small wiring labels require zooming. Some pages contain headings only or truncated text, including the Fuel Line Leakage Test entry.

One printable English PDF contains 1,267 pages: one cover page, one contents page, one foreword page, and 1,264 remaining manual and illustration pages. Repeated illustration pages are included in that total.