Proportioning Valve

Only vehicle without ABS have proportioning valves. Vehicles with ABS have Electronic Variable Brake Proportioning (EVBP) which is built into the ICU. On non-anti-lock master cylinder, 2 screw-in proportioning valves are screwed directly into the rear brake outlet ports. The chassis brake tubes lead to the rear brakes attach to the outlets of the proportioning valve. One proportioning valve controls each rear brake. Proportioning valves balance front to rear braking by controlling the brake fluid hydraulic pressure to the rear brakes about a preset level (split point). Under light pedal application, the proportioning valve allows normal fluid flow to the rear brakes. Under higher pedal effort, the valve reduces fluid pressure to the rear brakes. This helps prevent rear wheel skid tendencies.