Brake Proportioning/Combination Valve: Service and Repair

Removal Procedure

Important: Note the identification code on the valve. Have the proper code when ordering a replacement valve.





1. Raise the vehicle and properly support it with safety stands.
2. Remove the retaining bolts from the shield.
3. Remove the shield.





4. Disconnect the 2-way electrical connector from the combination valve.





5. Disconnect the front and rear brake pipes from the combination valve.





6. Remove the Allen bolts that fasten the combination valve to the BPMV.
7. Remove the combination valve from the BPMV.
8. Install the transfer tubes to the valve.

Installation Procedure

Important:
^ Do not reuse the old transfer tubes. Always install new transfer tubes with a new combination valve.
^ Ensure that the replacement combination valve has the same pin punched identification code as the old part.





1. Install the transfer tubes into the combination valve until the transfer tubes are fully seated.
2. Install the combination valve to the BPMV.

Notice: Refer to Fastener Notice in Service Precautions.

3. Install the Allen bolts to the combination valve and the BPMV.
^ Tighten the Allen bolts of the combination valve to 8 Nm (6 ft. lbs.).
^ Tighten the Allen bolts of the combination valve a second time to 16 Nm (12 ft. lbs.).





4. Connect the front and rear brake pipes to the combination valve.
Tighten the brake pipe fittings to the combination valve to 30 Nm (22 ft. lbs.).





5. Connect the 2-way electrical connector to the combination valve.





6. Install the shield to the vehicle.
7. Install the retaining bolts of the shield.
Tighten the retaining bolts of the shield to 12 Nm (8 ft. lbs.).

Important: Make sure that the metering rod of the combination valve is depressed during bleeding.

8. Bleed the brake hydraulic system. Refer to Hydraulic Brake System Bleeding (Manual) or Hydraulic Brake System Bleeding (Pressure Bleeding) in Brake Bleeding.
9. Return to Combination Valve Circuit.