I changed the booster and MC in my 37 cpe yesterday,The MC was leaking brake fluid in back which ruined the diaphram in the booster-
I bought a new MC w the correct piston Dia. + rod hole (Deep) in the primary piston and a used 68 Chevelle Booster ,Now When I step on the brakes the booster energizes all the way ,locks the brakes up and stay's that way for a minute B4 slowly coming back up to normal and releases the brakes, I can release them manually w my foot,when I disconnect the vac source the brakes act as they should ????? Now what???????