PB 150 V8-318 5.2L VIN T 2-BBL (1983)
Brake Proportioning/Combination Valve: Testing and Inspection
A visual check will show that the valve stem extends slightly when the brakes are applied and retracts when the brakes are released.
In Case of Malfunction
In case of a hold-off valve malfunction, remove the valve and install a new combination valve assembly.
CAUTION: Follow correct procedure to bleed the hydraulic system on vehicles equipped with hold-off valves.