COLLAR 9H7755 - Caterpillar

Sudden movement or accidental starting of the machine can cause personal injury or death to persons on or near the machine.To prevent personal injury or death, perform the following:Park the machine on a smooth, level surface.Lower the work tool to the ground and engage the parking brake.Stop the engine and remove the key.Block the wheels and install the steering frame lock.
Table 1
Required Tools
Part Number Description Qty
8T-0850 Pressure Gauge 1
1U-5482 Pressure Adapter Group 1 The pilot oil for a dead engine is supplied by oil in the lift hydraulic circuit. The pilot oil is used in order to lower the implements to the ground when the engine is off. The high-pressure oil in the lift cylinders is reduced by the pressure reducing valve to a reduced pilot oil pressure. The reduced pilot oil pressure must be less than the pilot pump oil pressure.
Illustration 1 g02549781
Diagnostic lines
Location of pressure tap for pilot supply oil
The diagnostic lines are located on the loader frame to the right of the articulation joint.
Connect the steering frame lock link.
Attach a 8T-0850 Gauge ( 4000 kPa (580 psi)) to the pressure tap for pilot supply oil.
Engage the parking brake.
Shift the transmission to neutral.
Start the engine. Warm the hydraulic oil to normal operating temperature of approximately 49 to 65°C (120 to 150°F).
Raise the boom off the ground.
Stop the engine. Record the gauge reading.
Turn the key start switch to the ON position and lower the implement to the ground.
The pilot oil pressure for a dead engine should be 1580 150 kPa (230 20 psi).
The pressure control valve must be adjusted if the pilot oil pressure for a dead engine is not correct.
Illustration 2 g02527579
Left main control valve (front view)
(1) Adjustment screw
(2) Locknut
(3) Pressure reducing valve
Loosen locknut (2).
Turn adjustment screw (1) clockwise in order to increase the pilot oil pressure for a dead engine.
Tighten the locknut. Perform Testing and Adjusting, "Pressure Reducing Valve Pressure for Dead Engine Pilot Supply (Engine OFF) - Test/Adjust" again in order to verify the new setting.