deward

My wife has a 1949 Chevy pick-up with a 1978 Monte Carlo Stub, and all Monte running gear including the brakes. The brakes are power with disc on front and drums on rear. The brakes will not lock up on a panic stop, front or rear. Could this be a bad booster or master cylinder? I appreciate any and all help. Thanks.

chevyfireball

Are you running a proportioning valve; monte brake booster? What engine is it running. Could be it ain't making enough vacuum for the booster. I had a major prob with a similar brake set up on my 69 Camaro when I put in a 572ci. I had to fit an electric vacuum pump by Stainless Steel Brake Corp. It pumps up the booster and then shuts off. F*&%k did it make a difference.

deward

It has the entire system from the Monte Carlo donor car. The truck only has a mild lift cam (488) and makes good vacuum with the 305 SBC. In a panic stop the brakes just slow down the truck but not like they should. I have to get this thing fixed fast. My wife wants to cruise and she wants to cruise now.
I think I may just replace the booster and master cylinder and see if that cures it. Thanks for your reponse.

chevyfireball

Does the pedal go rock solid or sink slowly to the floor?

deward

The pedal stays firm, but still don't have enough clamping force on the rotors.

fla1976

Sounds like the booster isn't operating. Disconnect the vacuum from it and try it again. If there is no difference, I'd replace it.

deward

I'm going to replace the booster and master anad I'll let you know what happens. Thanks to you guys for your advice. Hopefully we will have my wife cruising soon.