Brakes locking down, not releasing. new brake booster.working great. had to jam on brakes today. and the seem to not be releasing. had to get it home dragging a bit made it home ok. aprox 3/4 mile. pulled vacume hose to see if it would release. nope. put it back on and tested. like no booster . any help would be great. thanks. engine is a 383, with 4 drums. thanks again....troy jones