Brake Proportioning/Combination Valve: Testing and Inspection
PROPORTIONING VALVE FUNCTION TEST1. Connect two pressure gauges, one on the input side and one on 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 permissible ranges as illustrated, the proportioning valve is good.
3. Reconnect the brake lines in original position and bleed the system.