Rear Brakes

[STEPHEN F. ZEGLIN]

Im having a problem getting air in my back brake's, Ive replaced the pad's, caliper's
roter's, and master cylinder. But everytime I bleed the brake's they work OK for a
while then the pedal goes down again, bleed the brake's again and find air in the back
brake's, the system is not leaking or loosing any brake fluid.
This is on an 81.


Thank you

Steve

[bradfordsvettes]

you need to check the runout of the rotors if it is to high it will pump air into the system by moving the pistons back and forth. bad bearings could also add to your problem.if it is a runout problem some people install o-ring calipers that are less prone to pumping but I suppose it is a bandaid because the runout is out of spec. If it is a bearing issue get it fixed it is not a pretty picture if they fail and very expensive if let go Steve

[Eddie 70]

Bradfordvettes is correct. Runout seems to be your problem. You can shim the rotors by using spacers/shims behind the rotors. Take a dial indicator and measure the runout. You want to get the total runout as low as possible. If you can get it less than .005" total you should be in good shape for a while.