Brake problem

If the master cyl was removed or replaced, the push rod may need to be adjusted (shortened). If the push rod is too long, it will not allow all of the brake fluid to return to the master reservoir. When the fluid heats up, it has no were to go except to push the caliper pistons against the brake pads.

If you think that this may be the problem, create the brake drag problem. Stop the car on level ground and loosen the nuts attaching the master cyl to the brake booster. Pull the master away from the booster slightly (1/8" to 1/4" should do). You may have to use a wedge (screw driver) to pull them apart and keep them separated. Now see if the car will move by pushing the car.

John

quote:

Pull the master away from the booster slightly (1/8" to 1/4" should do).

Excellent advice.

And if in fact ALL four corners are sticking - kind of hard to tell unless you jack the car off the ground - it is most likely the MC push rod length.

You might be able to check this more easily in your garage, too.

The push rod should not be under any tension when installed. Loosening like John advised is step one. Then push the MC back to the booster. If you feel any tension (that is, the rod is pushing the MC piston seal) before it seats, the rod is too long.

Next idea...

Are your calipers used? If so, they may be sticking. However, for all 4 corners to stick would be quite unusual, though.

Check things out and get back to us.

Larry

Interesting thread. Now I am wondering if I have the same problem of a slightly too long master cylinder rod - but not as bad as described here. It has been baffling me a bit, since it is quite noticeable that the car rolls easily when cold, but often does not roll easily after I have been driving for a while. If I put my hand on the wheels, then all 4 are warmer than I would expect from normal driving. The back two calipers have been rebuilt last summer since there was clearly a problem with one of them sticking. I have an aftermarket Ford master cylinder, not the usual Pantera one. Will have to investigate a bit more and see if there is some adjustment on the master cylinder rod.
Cheers, Tim.

quote:

but often does not roll easily after I have been driving for a while.

Tim,

It is not uncommon for the car to require slightly more effort to roll after driving.

You can put shims between the master cyl and the booster and go for a drive. Use fork type wheel alignment shims or cut a small section from a flat washer (probably several washers) so that it just slips over the booster stud. Tighten the nuts (or bolts) and go for a drive. Be aware that the brake pedal will travel farther than you are used to.

John

Hi John,
thanks for the advice,
Cheers, Tim.

Hi Tim,

Let us know if it helps.

John