hello all, I am working on a 64 Chevy Pickup. Inspected the brakes and found all wheel cyl were leaking and the shoes looked like ****.I replaced all cyl with new not reman ,new shoes,new master cyl not reman,new hoses front and rear,adjusted shoes to stiff drag.I have bleed the wheel cyl till positively no air also benched the master before install.With engine not running the pedal is about half way up almost even with gas pedal,good solid pedal.OK start the engine,pedal goes straight to the floor. With heavy foot pressure the brakes will hold,but should not be on the floor.What are your thoughts, maybe someone has put in a different brake rod,the one behind the master cyl?
You didn't state that it had power brakes but from what your saying it must. Check engine vac***n and then I think you need a new boster if you didn't do that already. My $0.02.
Pull of the master cyl and measure the depth from mounting flange to bottom of hole in M/C piston bet the new one is deeper. Years ago a lot of vehicles took different M/Cs power V/S standard.
I have a 64 pickup as well, but I have Disc's in front, and a 81 Caprice rear end, ( In the truck, I know how you guys think) just to be different and it was free! First thing I thought of was to tighten up on the adjustment until you have a little drag at each wheel. Just my two pennies, don't spend them all at one place!!
Did you have a good pedal before the brake job? I am kinda doubting two things.."new master cylinder" Who makes a brand new M/C? Probably rebuilt. Next is what method did you use to bleed the brakes? I believe you have either [from your description] air in the system or a defective master cylinder....as long as you have installed all of the brake parts on each wheel correct.
The rods that come out the booster are never really equal.Just like above said. Unbolt the master cylinder and look whats going on. If the pin is non adjustable put a short bolt in between,or some kind of homebrew spacer until you get a slight preload when bolting on the master. I'm pretty shure theres a huge gap and no preload at all! When the booster comes in the pedal always goes down a bit. So you need to have it all the way up,without vacuum/engine runnin... good luck, OldschoolOlli
moter the master cyl is a new a1 cardone not a reman so I was told. As for the bleeding of the brakes it was the old you pump and i'll bleed method I always get stuck in the truck thats on the lift doing the pumping wears my legs out!
Being that it is A1 Cardone it is probably reman. The best way to bleed is RR,LR,RF,LF. A cheater way to fiqure out if you have air in the system or a bad master is..get a pair of vise grip pliers and lightly crimp all the brake hoses. Now push on the brake pedal. If the pedal goes to the floor the master is bad. If the pedal is rock hard..keep pressure on the pedal, then release the rear clamp first, then rf and lf. When the pedal drops you have air in that part of the system....Flame suit on ..I know its not the perfect way to check for air, and most ppl do not aprove of it. but it will direct your to the part of the system with the air..
FWIW I started using speed bleeders, less than $25 for all 4 wheels and it makes bleeding brakes easy. Just gives you one less thing to have to worry about when you're figuring out problems.
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