Brake Proportioning/Combination Valve: Service and Repair

PROPORTIONING VALVE

REMOVAL

NOTE: Before proceeding, Refer to Service Precautions.





1. Using a brake pedal holder, depress the brake pedal past its first one inch (25 mm) of travel and hold it in this position. This will isolate the master cylinder from the brake hydraulic system and will not allow the brake fluid to drain out of the master cylinder reservoir.





NOTE: To access the lower (left rear) proportioning valve, it may help to remove the air cleaner cover and hose to the throttle body.

2. Disconnect the brake tube (4 or 5) from the proportioning valve requiring removal.





3. Unscrew the proportioning valve (1 or 3) from the master cylinder (2).

INSTALLATION





1. Lubricate the O-ring on the proportioning valve. If not new, replace the 0-ring on the proportioning valve.
2. Install the proportioning valve (1 or 3) in its master cylinder (2) port. Tighten the proportioning valve to 27 Nm (20 ft. lbs.).





3. Install the brake tube (4 or 5) to the proportioning valve. Tighten the tube nut to 17 Nm (145 inch lbs.).





4. Remove the brake pedal holder.
5. Bleed the affected brake line.
6. Road test the vehicle to ensure proper operation of the brakes.