John Deere 450G, 455G, 550G 555G, 650G Crawler Operation and Test Technical Manual (TM1403)

Hydraulic temp light pops on, machine loses push, operator’s freaking out. You’ve got two choices: guess and start throwing parts, or open TM1403 and run the exact operational checkout John Deere wrote for these 450G–650G crawlers. That book tells you where to put the gauges, what pressures you should see, and in what order to test so you’re not chasing ghosts and wasting half a day.

Key Tasks Covered:

• Run full operational checkout sequence before teardown.
• Verify steering and brake pressure with correct test ports and specs.
• Diagnose charge pressure loss in the hydrostatic system.
• Track down no-crank issues in the starting/charging circuit.
• Interpret warning lights using factory sensor and switch logic.
• Check engine performance under load with proper RPM and temp ranges.

Common Questions:

Q: “Steering’s weak on one side. Where do I start instead of ripping into the finals?”

A: TM1403 has you check hydrostatic charge pressure, steering valve spool leakage, and pilot pressure first—final drives are last, not first.

Q: “Machine won’t move, engine’s fine. What now?”

A: Follow the transmission neutral start and seat switch tests, then verify servo pressure at the HST—usually a control issue, not a blown pump.

Safety Note

Don’t bypass safety switches just to “see what happens.” You’ll only get one chance if it lurches.

John Deere 450G, 455G, 550G 555G, 650G Crawler Index:

General Information
Operational Checkout Procedure
Engine
Electrical System
Power Train
Hydraulic System

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