ENGINE AR 9Y5555 - Caterpillar

Do not adjust the main relief valve above the specified pressure. Adjustment of the main relief valve above the specified pressure may cause damage to the gear pump.
The following test is performed in order to determine if the main relief valve for the work tool is damaged or improperly set.
Engage the parking brake. Stop the engine.
Raise the cab. Refer to Operation and Maintenance Manual, "Cab Support Operation" for the proper procedure.
Illustration 1 g01055240
(1) Test port
Install the 8T-0860 Gauge to test port (1) with a 177-7861 Hose .
Route the test hose so that the cab will not rest on the hose. Securely bolt the cab to the frame.
Sit in the operator's seat. Fasten the seat belt. Lower the armrest. Start the engine. Disengage the parking brake.
Set the engine to HIGH IDLE.
Illustration 2 g00788651
Pilot operated hydraulic control ( work tool)
Move the pilot operated control lever for the work tool to the full LOWER position. Hold the control lever until the lift arms are fully lowered and a stall condition exists. Note: Do not stall the hydraulic system for more than 10 seconds. If necessary, release the work tool from the stall condition. Release the work tool for 30 seconds and repeat the following step.
Record the system pressure for the work tool during the stall condition. Move the control lever for the work tool to the NEUTRAL position.
Table 1
MAIN RELIEF PRESSURE    
Machine     Serial Numbers     Main Relief Pressure    
216B
232B     RLL1-6799
SCH1-2474    
21400 700 kPa (3104 102 psi)    
216B
226B
232B
242B     RLL6800-Up
MJH1-Up
SCH2475-Up
BXM1-Up    
23000 700 kPa (3336 102 psi)    
Release the hydraulic control from the stall condition. Tilt the work tool until the work tool is parallel with the ground. Stop the engine.
If the pressure reading is within specifications, proceed to step 23. If the pressure reading is not to specifications, the main relief valve needs to be adjusted. Proceed to step 11.
Release the hydraulic system pressure. Refer to Testing and Adjusting, "Hydraulic System Pressure - Release" for the proper procedure.
Raise the cab of the machine.
If your machine uses a relief valve (Type 1) then proceed to Step 14. If your machine uses a relief valve (Type 2) proceed to Step 18.
Illustration 3 g01383119
Main relief valve for the work toolNote: The following steps are for machines that use a relief valve (Type 1).
Illustration 4 g01355287
(2) Main relief valve (Type 1) for the work tool (3) Cap (4) Locknut
Remove end cap (3) from main relief valve (2) .
Loosen locknut (4). The adjustment screw is under the end cap (3). Turn the adjustment screw clockwise in order to increase