3.
With the brakes applied, measure the input pressure and the output pressure. If the measured pressures are within the specified range, the proportioning valve is good.
Remove the proportioning valve from the master cylinder.
Connect two pressure gauges; one to the input side, and one to the output side.
Be sure to bleed the system after connecting the pressure gauges.
With the brakes applied, measure the input pressure and the output pressure. If the measured pressures are within the specified range, the proportioning valve is good.
Reconnect the brake lines in their original positions and bleed the system.
This figure shows characteristics of the proportioning valve as the pressure increase.
