On some early models, this valve was called the brake control valve assembly. Integral with this early unit was the proportioning valve and together, they are the same unit as the pressure control valve on later cars.
There are two pressure control valves housed in the master cylinder assembly. The valves reduce rear brake system hydraulic pressure when the pressure exceeds a preset value. The rear brake hydraulic pressure is limited in order to minimize rear wheel skidding during hard braking.
REMOVAL & INSTALLATION
Early Model Vehicles
- Unplug the brake warning light switch wire harness connector from the warning light switch.
- Disconnect the front brake system inlet tube and the rear system inlet tube from the control valve assembly.
- Disconnect the left and right front brake outlet tubes from the brake control valve system.
- Disconnect the rear system outlet tube from the control valve assembly.
- Unfasten the screw that attaches the valve to the fender apron bracket and remove the valve.
The control valve is not serviceable and must be replaced if any part of the assembly is defective.To install:
- Install the control valve onto the bracket on the fender apron, then install and tighten the mounting screw to 13-25 ft. lbs. (18-33 Nm).
- Attach the rear brake outlet tube to the control valve assembly and tighten the tube nut to 10-18 ft. lbs. (14-24 Nm).
- Attach the right and right front brake outlet tubes to the valve assembly and tighten the tube nuts to 10-18 ft. lbs. (14-24 Nm).
- Attach the front brake inlet tube to the control valve assembly and tighten the tube nut to 10-18 ft. lbs. (14-24 Nm).
- Attach the brake warning light switch electrical connection.
- Bleed the brake system.
- Disconnect the primary or secondary brake line, as necessary.
- Loosen and remove the pressure control valve from the master cylinder housing.
- Install the pressure control valve in the master cylinder housing port and tighten to 10-18 ft. lbs. (14-24 Nm).
- Connect the brake line and tighten the fitting to 10-18 ft. lbs. (14-24 Nm).
- Fill and bleed the brake system.