QuestionDick, I have purchased an original 54 Buick Roadmaster. The previous owner removed alot of the vacuum lines when the fuel/vacuum pump quit working. I have just finished rebuilding the pump and I am looking for a diagram that shows how everything is connected. Also the power brakes don't work. I suspect it may part of the vacuum problem. Can you help I have looked everywhere.
AnswerI don't have a diagram either, but I can tell you what is connected to what:
The brake booster needs a major source of vacuum, and that will have to be from a large hose that goes to the intake manifold or to the base of the carburetor. The power brake booster has an associated vacuum reservoir, most likely hidden in the left front fender, which is tee'd into the vacuum line from the intake manifold, with a check valve at the manifold to prevent the vacuum from disappearing instantly if the engine should stall. The reservoir maintains enough vacuum to allow 3 full stops before the tank is exhausted.
The other vacuum lines and connections are independent of the braking system.
There will be a small vacuum line which goes from an intake manifold fitting to the side of the vacuum section which pumps air out. The opposite side of the vacuum pump pulls vacuum on whatever is hooked up to it, which in your car includes the windshield wiper motor, and perhaps other vacuum operated accessories if the car has them.
Vacuum hoses are specially made for that purpose, do not use fuel hoses, as they will collapse under vacuum. The NAPA store can help you with both power brake hose and wiper hose - just measure the size of the fittings.
Dick
