xrated

When i bought my 72 vette we discovered there was no fluid in the rear brake resovoir. The master cyl had a leak and i have no idea how long it was being driven with front brakes only..(it still stopped fairly well). I had the master cyl reconditioned and now my brakes are seizing. I am pretty sure its only one on the rear. When cold everything is fine...but after driving for a while it gets prgressively worse. On top of this the Pedal travel is normal at first but goes rock hard once the brakes begin to stick...this indicates to me that theline may have rust in it..which has now jammed the caliper pistons. Is my assumption correct?
Is there any way to flush out the rust from the brake line...I really dont want to go through the hassle of changing them...what if I pump fluid through them with no caliper on the end?
I first thought it was the handbrake seizing but this would not explain the pedal getting hard.
:confused:

lyonsh

Yes, you can flush our your lines, either with clean brake fluid or denatured alcohol. In fact, I'd suggest you try a system flush (bleed the brakes until the fluid comes out clean) as the first step in fixing the problem. If you have a lot of water in the system, that can boil and lock up your brakes.

If that doesn't work (you may have to bleed 2 or 3 times - C3 brakes are notorious for being a pain), post back again - there's a couple of other possibilities, too.

bob

Sounds like a possible deteriorated rubber flex line. They often fail in such a way that it acts as a one way check valve and give exactly your symptom.
bob

xrated

Thanks guys... found the problem.
Calipers are OK. When the master cylinder was recon-ed they put a new piston in it. After loosening the master cyl bolts a turn the brakes let go. We think the new piston may be slightly longer. To compensate for this we are going to shorten the adjustable ram from the booster. Easy fix! :cheers: