I'm working on the brakes of a friends '95 Nissan Pathfinder w/180k miles.
The problem is that the brakes won't let go. Driver can hear them when driving and the wheel gets very hot. After noticing that (a) the calipers were very hard to extract from the brake pads; it took a lot of prying to get it off, and (b) once the caliper was separated from the pads, the caliper pistons won't push back in with a c-clamp, we concluded that the calipers were defective and replaced both front calipers with re-manufactured units from Pep Boys. This is the second pair of front calipers installed in this truck within the last year
After installing the new calipers and bleeding the brakes, I noticed that after applying the brakes and then releasing them, the wheel is still hard to turn by hand. The pads are clearly still holding on tightly to the disk. Sure enough, after putting the car back into service, the problem persists. Driver indicates that if he pumps the brakes a few times he can get them to release temporarily. I am begining to suspect the master cylinder. It seems as if fluid is being pumped OUT of the master cylinder but can't return.
Questions:
- Is this a typical/possible failure mode for master cylinders?
- If not the master cylinder, what else would cause this?