Brake Proportioning/Combination Valve: Testing and Inspection

1. Connect two pressure gauges, one each to the input side and output side of the proportioning valve, as shown.
2. Air bleed the brake line and the pressure gauge.
3. While gradually depressing the brake pedal, make the following measurements and check that the measured values are within the allowable range.










Standard Value Chart

1. Output pressure begins to drop relative to input pressure (split point).





Test Charts

2. Check that the output fluid pressure is at the standard value when the input fluid pressure increases according to the table below.
3. Output pressure difference between left and right brake lines
Limit: 0.4 MPa (57 psi)
4. If the measured pressures are not within the allowable ranges, replace the proportioning valve.