Originally Posted by Flye
68 Original Front Disks
First time out for 'longer drive' today. Entire brake system has been redone, as car had 'sat' for almost 30 years. I'll skip details and go to point:
Front brakes are evidently not totally releasing, which is keeping tension/friction on the front pads > heat > almost locking.
When they cool, the wheels will turn by hand, but barely.
I loosened bleeders, tightened, and they were fine.
Took it out, and they got tight again.
Pedal seems fine, and brakes operate fine, but it is not driveable as is.
Rear turned fine, so it is all front oriented.
Rebuilt calipers (Advance or wherever).
Service manual indicates more of an issue of the pistons not releasing in caliper sleeve?
If I'm not mistaken, I'm using original master cylinder with a rebuild kit in it, that had also been sleeved by Apple.
Is there anything in master cylinder operation that could lead to holding pressure on the fronts?
If so, the easiest thing to first replace is to put a different MC on it, as I have both a fully rebuilt orginal, as well as a parts store rebuild.
Thanks for thoughts....
All the ideas presented are good areas to check
As you mention yourself.....rebuilt calipers.
Don't discount that they may be playing into your
The square cut seal and the overall condition of
the seal's land in the caliper bore are the main
as far as how much the piston
returns back into the bore after you release the
brake pedal..... at least when you're purely
talking about the caliper, apart from the system
as a whole.
Brake Systems Engineering Center
Farmington Hills, MI