Proportioning Valve Function Test < Vehicles Without Abs >

WARNING: This page is about a different car, the 2005 Mitsubishi Endeavor. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION: The proportioning valves are installed independently for the right and left brake lines. Always measure each valve.

Connect two pressure gauges to the output port of the master cylinder and output port of the proportioning valve.
Bleed the brake line and the pressure gauges (Refer to BLEEDING ).

Fig 1: Connecting Pressure Gauges To Output Port Of Master Cylinder And Proportioning Valve
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
Depress the brake pedal gradually. Then check that the split point, where the output fluid pressure begins to drop in proportion to the output fluid pressure, is at the standard value.
- Standard value: 3.19 - 3.67 MPa (463 - 532 psi)
  
  Fig 2: Identifying Split Point
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
Depress the brake pedal more strongly than at the above step. Then check that the output fluid pressure is at the standard value when the input fluid pressure is 7.35 MPa (1,066 psi).
1. Standard value: 4.17 - 4.66 MPa (605 - 676 psi)
Measure each output fluid pressure at both valves, and check that the difference between the two is at the limit value or less.
1. Limit: 0.5 MPa (73 psi)
If the measured pressure exceeds the limit, replace the proportioning valve.