ROD AS 2898621 - Caterpillar

Illustration 1 g00495742
Adjust the main relief valve.
Loosen jam nut (26). Maintain the position of adjustment screw (27). Note: One turn of the adjustment screw causes the main relief valve pressure to change by an increment of 235 kPa (34 psi).
Turn adjustment screw (27) until the desired rotation is attained.
Do not allow adjustment screw to rotate when the jam nut is tightened.
Tighten the jam nut to a torque of 18 4 N m (13 3 lb ft).Refer to Testing and Adjusting, "Pressure Taps".Refer to Testing and Adjusting, "Pressure Charts".Expected Results
The correct main relief pressure is attained.
The original complaint is resolved.Results
OKAY: Stop.
NOT OKAY: Proceed to Step 7.
Perform the procedure that is referenced.Refer to "System Pressure Is Low" in this manual under Troubleshooting, "Oil Pressure Troubleshooting".Results
REPAIRED OKAY: Stop.
NOT OKAY: Proceed to Step 8.
Illustration 2 g00495744
(3) Priority valve group (4) Inlet relief valve (torque converter) (28) Adjustment screw (29) Adjustment screw (C) Torque converter inlet (pressure tap) (K) Priority valve (pressure tap)
Personal injury can result if the machine moves while testing.If the machine begins to move during test, reduce the engine speed immediately and engage the parking brake.
Measure the pressure at the torque converter inlet.Note: Measure the pressure when the oil is cold. Do not allow the machine to reach the normal operating temperature before you measure the pressure.Perform the following procedure in order to adjust the pressure for the torque converter inlet. The priority valve group contains the priority valve and the torque converter inlet relief valve.If the setting at the torque converter inlet is low then the valve may be directing oil back to the tank. Therefore, the oil does not go through the oil cooler. This can cause the system temperature to increase. Observe the oil path in Testing and Adjusting, "Schematic".
Start the engine. Measure the pressure from the pressure tap. Note the pressure.
Turn off the engine.Reference: Testing and Adjusting, "Pressure Charts"Reference: Testing and Adjusting, "Pressure Taps"Expected Results
The pressure is correct.Results
OKAY: Stop.
NOT OKAY: Change the oil