Proportioning Valve

Install pressure gauge and "T" fitting between HCU and male end (master cylinder inlet) of faulty proportioning valve. See PROPORTIONING VALVE IDENTIFICATION table. Install another pressure gauge at female end of proportioning valve.
Have an assistant hold brake pedal down to obtain master cylinder pressure reading on inlet gauge. Check reading on outlet gauge. Compare readings to specification. See BRAKE PRESSURE table. If readings are not as specified, replace proportioning valve.

PROPORTIONING VALVE IDENTIFICATION

Body

Application

⁽¹⁾ Split Point/Slope

All Models

14" Wheel Disc/Disc

435 psi/.43

WHT

⁽¹⁾	Split point is when proportioning valve changes rear brake pressure to prevent skidding. Slope is the pressure differential (percentage ratio) between front/rear brakes.

BRAKE PRESSURE

Master Cylinder Pressure

⁽¹⁾ Split Point/Slope Outlet Pressure

Rear Brake

1000 psi

441 psi/.45

640-720 psi

1000 psi

515 psi/.45

685-765 psi

1000 psi

588 psi/.45

725-805 psi

1000 psi

662 psi/.45

765-845 psi

1000 psi

294 psi/.30

460-540 psi

1000 psi

368 psi/.30

510-590 psi

1000 psi

441 psi/.30

560-640 psi

⁽¹⁾	Split point is when proportioning valve changes rear brake pressure to prevent skidding. Slope is the pressure differential (percentage ratio) between front/rear brakes.