BODY-RETARDER CONTROL VALVE 8P7702 - Caterpillar

Adjustment Procedure:
1. Install a pressure gauge that will read from 0 to 690 kPa (0 to 100 psi) in retarder valve outlet port.2. The air system must be fully charged when this adjustment is made.3. Move the control handle to the "full applied" position and make a note of the pressure. This valve will have lower outlet pressures at positions other than "full applied."4. Remove the head and the lock ring from the valve.5. Turn the adjusting ring clockwise to increase the outlet pressure and counterclockwise to decrease the pressure.6. When the pressure is correct, install the lock ring so it will hold the adjusting ring in position. Install the head of the valve.Make a note of this new adjustment procedure in your Service Manual.
After the retarder performance factors have been checked and the retarder valve air pressure is correct, the performance of the retarder can be checked. With the engine and transmission at normal operating temperature - the transmission in neutral - the brakes applied - and the engine rpm at high idle, move the handle on the retarder valve to the "full applied" position. The engine rpm must now be 1790 140. If the engine rpm is not correct, see the retarder troubleshooting section of your Service Manual.
Location of head and lock ring in the retarder valve assembly.