HARNESS AS 2W8902 - Caterpillar

Personal injury or death can result from sudden machine movement.Sudden movement of the machine can cause injury to persons on or near the machine.To prevent injury or death, make sure that the area around the machine is clear of personnel and obstructions before operating the machine.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting, and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.Refer to Special Publication, NENG2500, "Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Cat products.Dispose of all fluids according to local regulations and mandates.
Use this procedure to verify the relief valve pressure setting for the pilot hydraulic oil system.Note: The hydraulic oil temperature is to be warmed to a minimum of 65° 3°C (150° 5°F)
Illustration 1 g02702476
Illustration 2 g02702496
Location of the Pressure Tap for the Pilot Oil System
View from the top of the machine
Table 1
Necessary Tools
Part Number Description Qty
4C-4890 Hydraulic Test Group(1) 1
4C-4892 ORFS Fittings 1
(1) The 198-4240 Digital Pressure Indicator can be used to check the pressure.
Position the machine so that the machine is in the STRAIGHT AHEAD position.
Illustration 3 g01149567
Move the steering frame lock into the LOCKED position.
Engage the parking brake. Move the transmission direction control switch to the NEUTRAL position.
Shut off the engine.
Move the control levers to all the positions in order to release any pressure that is in the pilot system.
Illustration 4 g02702919
Illustration 5 g02702837
Hydraulic Breaker Relief Valve (Top of the Loader Frame)
Press the hydraulic breaker relief valve for the hydraulic tank in order to release the pressure in the tank. Slowly loosen the tank filler cap in order to release any remaining pressure that is in the tank. Tighten the cap.
Remove the cap from the pressure tap. Install 8T-0856 Pressure Gauge and a hose assembly.
Start the engine. Run the engine at low idle. Move the lift control lever and the tilt control lever to all the positions. The pressure reading must be 3450 350 kPa (500 50 psi).
Run the engine at high idle. Move the lift control lever on the pilot valves and the tilt control lever on the pilot valves to all the positions. The pressure must remain identical in all the positions.
Illustration 6 g02702922
Illustration 7 g02581460
Location of the Pilot Relief Valve on the Loader Frame
(2) Pilot relief valve.
Illustration 8 g01142439
Cross section of the Pilot Relief Valve
(2) Pilot relief valve. (3) Locknut. (4) Adjuster.
If the pressure is not within the specifications, adjust pilot relief valve (2). Loosen locknut (3).
Turn adjuster (4) clockwise in order to increase the pressure. Turn the adjuster counterclockwise in order to decrease the pressure. For each 1/4 turn, the pressure will change approximately 745 kPa (108 psi). Tighten locknut (3).
Check the pilot relief pressure setting in order to be certain that the setting is within the specified range. Note: If the setting of the selector and pressure control valve will be checked, do not remove the pressure gauge.