74' truck problems with brakes.

[charger72]

I have a 74' Pw that I recently put on new pads on all 4 drums and new lines in the front and also had to repelace a leaking front brake hose.. But now I am getting a spongy brake pedal with the brakes pulling to the left alot. And every now and then the brakes stop fine but still pull. It has a 1 year old master cylinder on it. I do notice that with the motor off I get a stiffer brake pedal than when it is running now. Could my booster or proportioning valve be going bad? also, I always have since I had the truck when I push in the brake it sounds like a vaccum leak, but non has ever been found and the brakes have worked before.
All help is appreciated.

[Todd Wilson]

I have a 74' Pw that I recently put on new pads on all 4 drums and new lines in the front and also had to repelace a leaking front brake hose.. But now I am getting a spongy brake pedal with the brakes pulling to the left alot. And every now and then the brakes stop fine but still pull. It has a 1 year old master cylinder on it. I do notice that with the motor off I get a stiffer brake pedal than when it is running now. Could my booster or proportioning valve be going bad? also, I always have since I had the truck when I push in the brake it sounds like a vaccum leak, but non has ever been found and the brakes have worked before.
All help is appreciated.

I think you have a few problems going on at the same time. I would say your right side isnt bled good enough or the self adjusters arent working and your brakes are loose on the right side. Left side is working better and pulling you on application.



I would say your booster has probably got a leak. I had mine leak on my 74 Dodge. Brakes still worked just fine but it was creating such a bad vacuum leak the 440 didnt want to run good. After checking all the normal tune up stuff it still ran like crap and acted like a vacuum leak but couldnt find one on the motor. I replaced it and everything was good after that! Be ready for a kick when you go get a new one. Expensive! 100$+ fro the booster.  They typically leak and then come back thru the seal into the cab there where the brake pedal rod goes thru. A booster vacuum leak can cause a lot of problems with the motor running more then the brakes. Very easy to get overlooked!


As far as I know the proportional valve controls front to back not side to side so I doubt its bad.


Todd