Brake Proportioning/Combination Valve: Testing and Inspection

1. Connect two pressure gauges, one to the input side and one to the output side of the proportioning valve.

NOTE Be sure to bleed the system after you connect the pressure gauges.

2. With the brakes applied, measure the input pressure and the output pressure. If the measured pressures are within the ranges as illustrated, the proportioning valve is good.
3. Reconnect the brake lines in their original positions and bleed the system.






NOTE This figure shown characteristics of the proportioning valve during pressure increase.

A: 51 +/- 3.5
B: 80
C: 40
D: 140
E: 67 +/- 4