PLATE 2825970 - Caterpillar

Note: Make sure that the filters and the screens are clean before you test any pressures. Make sure that the oil is at operating temperature before you perform this test.This test will determine if the operation of the dual stage relief valve and the setting of the dual stage relief valve are correct.
Personal injury or death can result from sudden machine movement.Sudden movement of the machine or release of air pressure or oil pressure can cause injury to persons on or near the machine.To help prevent possible injury before testing and adjusting any air system or hydraulic system, perform the procedure in the Testing and Adjusting, "General Information" section.
Procedure
Note: Perform Testing and Adjusting, "Gear Pump (Transmission Charging) Pressure - Test and Adjust" before you perform this test.
Disconnect the wire harnesses from the upshift solenoid, the downshift solenoid, and the lockup clutch solenoid.
Illustration 1 g00398587
(L) Pressure tap for the transmission charging pump section
Use two 6V-4143 Couplers and 177-7862 Hose Assembly in order to connect 8T-0855 Pressure Gauge to the nipple at pressure tap (L).
The downshift solenoid remains activated when the transmission is in NEUTRAL. The harness for the downshift solenoid will be used to supply power to the lockup clutch solenoid. The harness will supply +24 Volts to the lockup clutch solenoid.
Start the engine while the parking brake is activated. Run the engine at the low idle rpm while the transmission is in NEUTRAL-1. The pressure on the gauge must be 2515 kPa (365 psi) minimum. Note: In order to maintain 1300 rpm for this test, disconnect the throttle position switch. Then use the throttle backup switch.
Look at the pressure gauge and connect the electrical harness from the downshift solenoid to the lockup clutch solenoid. The pressure on the gauge must be 2100 105 kPa (305 15 psi). Run the engine at the medium idle rpm. The medium idle rpm is approximately 1300 rpm. The pressure on the gauge must be 2100 105 kPa (305 15 psi).
Run the engine at the low idle rpm. Disconnect the electrical harness connector from the lockup clutch solenoid. The pressure on the gauge must be at least 2515 kPa (365 psi).
Stop the engine. After the pressure is correctly set, remove the test equipment.
Illustration 2 g00554618
Selector and pressure control valve
(1) Dual stage relief valve
Illustration 3 g00554609
Pressure control valve
(2) Shims
(3) Modulation reduction valve
Table 2
Chart Of Shims
Station D(1)
Pt. No. for Shim Thickness Change in Pressure
5J-2721 Shim 0.13 mm (0.005 inch) 12 kPa (1.7 psi)
6J-3993 Shim 0.25 mm (0.010 inch) 25 kPa (3.6 psi)
4M-1751 Spacer 0.41 mm (0.016 inch) 39 kPa (5.7 psi)
5J-1036 Shim 0.79 mm (0.031 inch) 76 kPa (11.0 psi)
(1) Before an adjustment is made, be certain that the valve spring is not weak or broken.Use Illustration 2, Illustration 3, and Table 2 for the following problems.Problem: The oil pressure is not at least 2515 kPa (365 psi) with the lockup clutch solenoid deactivated.
Probable Cause
The lockup clutch solenoid is stuck open.
Modulation reduction valve (3)