Proportioning Valve

Proportioning valves balance front to rear braking by controlling the brake fluid hydraulic pressure to the rear brakes. 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.

The non-antilock master cylinder is a four-outlet design with two screw-in proportioning valves attached directly to the inboard side of the master cylinder housing. One proportioning valve controls each rear brake.

Fig 35 Type 3 Proportioning Valve Identification:

Due to differences in thread sizes between the two valves, each proportioning valve has a different part number. During any service procedure, identify the valve assemblies by the supplier part number and the color identification band.