Proportioning Valve

Install pressure gauges in master cylinder outlet ports equipped with proportioning valves. These gauges will measure hydraulic pressure to rear brakes. Install pressure gauges in remaining master cylinder outlet ports. These gauges will measure hydraulic pressure to front brakes. Depress brake pedal, and apply 850 psi test pressure to front brakes. Check proportioning valve outlet pressure. See PROPORTIONING VALVE TEST SPECIFICATIONS  table. If outlet pressure is not as specified, replace faulty proportioning valve(s).