All vehicles are equipped with a brake pressure control valve. On vehicles with anti-lock brakes, the valve assembly consists of twin brake proportioning valves, which proportion the pressure to both rear brakes, individually. On vehicles without anti-lock brakes, pressure control is installed into the master cylinder, and proportions pressure to the rear brake circuit through a junction block on the frame. When the brake pedal is applied, the full rear brake fluid pressure passes through the proportioning valves to the rear brake system until the valve-split point is reached. Above it split point, the proportioning valves begin to reduce the hydraulic pressure to the rear brakes, creating a balanced braking condition between the front and rear wheels.
Removal & Installation
- Disconnect the brake inlet lines and the rear lines from the brake control valve assembly.
- Remove the screw retaining the control valve assembly to the frame and remove the brake control valve.
- Position the control valve on the frame and secure with the retaining screw.
- Connect the rear brake outlet lines to the control valve assembly and tighten the line nuts to 10-18 ft. lbs. (14-24 Nm).
- Connect the inlet lines to the control valve assembly and tighten the line nuts to 10-18 ft. lbs. (14-24 Nm).
- Bleed the brake system.