Diesel Data: Automotive Repair

Brake Proportioning/Combination Valve: Service and Repair



Proportioning Valve Replacement

Removal Procedure

Caution: Refer to Brake Fluid Irritant Caution.

Notice: Refer to Brake Fluid Effects on Paint and Electrical Components Notice.





Important: Use tape to label and mark the locations of the brake pipes in order to aid in installation.

1. Disconnect the 2 brake pipes (1) from the proportioning valve. Use bleeder valve caps or similar caps to plug the ends of the brake pipes in order to prevent brake fluid from draining out of the pipes and to avoid brake fluid contamination.




2. Disconnect the 4 brake pipes (1) from the proportioning valve. Use bleeder valve caps or similar caps to plug the ends of the brake pipes in order to prevent brake fluid from draining out of the pipes and to avoid brake fluid contamination.




3. Remove the 2 proportioning valve bracket nuts and remove the proportioning valve assembly from the vehicle.

Installation Procedure





Notice: Refer to Fastener Notice.

1. Install the proportioning valve assembly and the 2 proportioning valve bracket nuts.

Tighten the 2 proportioning valve bracket nuts to 10 N.m (89 lb in).





Caution: Make sure brake pipes are correctly connected to brake pressure modulator valve. If brake pipes are switched by mistake, wheel lockup will occur and personal injury may result. The only two ways this condition can be detected are by using a Scan Tool or by doing an Antilock stop.

2. Remove the tape that marked the locations of the brake pipes.
3. Remove the caps from the 4 brake pipes (1) and install the 4 brake pipes (1) to the proportioning valve.

Tighten the brake pipe fittings to 20 N.m (15 lb ft).




4. Remove the caps from the 2 brake pipes (1) and install the 2 brake pipes (1) to the proportioning valve.

Tighten the brake pipe fittings to 20 N.m (15 lb ft).

5. Bleed the brake system. Refer to Hydraulic Brake System Bleeding (Manual), (Pressure).