POINT-CONTACT 1472057 - Caterpillar

Hydraulic oil pressure can remain in the hydraulic oil system on this machine after the engine and pump have been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic systems. To prevent possible injury, refer to the procedure in Testing and Adjusting Manual, "Release of Pressure in the Hydraulic System".When possible, the bucket must always be lowered to the ground before service is started. When it is necessary for the boom to be in the raised position while tests or adjustments are done, be sure that the boom, stick and bucket have correct support.Be sure the swing parking brakes and the travel parking brakes are on and the brake release lines are disconnected and plugged.Always move the machine to a location away from the travel of other machines. Be sure that other personnel are not near the machine when the engine is running and tests or adjustments are being made.
Table 1
Required Tools    
Part Number    Part Description    Qty    
4C-4892     ORFS Fittings Group     1    
8T-0857     Pressure Gauge     1    
8T-0856     Pressure Gauge     1    Note: Always warm the hydraulic oil to a minimum temperature of 50°C (122°F) before starting the testing and adjusting procedure.Note: Any change to the low pilot system pressure also changes the high pilot system pressure. Always set the low pilot system pressure before setting the high pilot system pressure.Low Pressure Pilot Relief Valve
Preparation
Illustration 1 g00434558
Pilot Manifold (1) Low pilot pressure tapConnect a 5515 kPa (800 psi) pressure gauge to low pilot pressure tap (1) on the pilot manifold.
Start the engine.
Warm the oil to a minimum temperature of 50 °C (122 °F). Refer to the Testing and Adjusting, "General Information" for the proper procedure for warming the hydraulic oil.
Set the throttle switch to position 3. The pilot pressure at the low pilot pressure tap (1) should be 4000 200 kPa (580 29 psi).
Illustration 2 g00434666
Pilot Manifold (2) Low pressure pilot relief valve
Illustration 3 g00434667
Pilot Relief Valve (3) Locknut (4) Adjustment screw
To adjust the pilot pressure for the low pressure pilot circuit, loosen the locknut (3) on the relief valve (2). Turn the adjustment screw (4) until the pressure gauge indicates 4000 200 kPa (580 29 psi). Tighten locknut (3) .Note: Always make pressure adjustments on the pressure rise.
With the engine at throttle position 1, verify that the low idle setting is at 725 20 rpm. The low pilot system pressure should be no less than 3100 kPa (450 psi). If the low pilot system pressure is less than 3100 kPa (450 psi), refer to Testing and Adjusting, "Hydraulic System Troubleshooting".High Pressure Pilot Relief Valve
Preparation
Illustration 4 g00434668
Pilot Manifold (5) High pressure pilot relief valve (6) High pilot pressure tap
Illustration 5 g00434669
Pilot Hydraulic Oil Filter (7) High pilot pressure tapConnect a 10000 kPa (1450 psi) pressure gauge to the high pilot pressure tap (6) at the pilot manifold or to the high pilot pressure