Both rear calipers locked up and then released??

[msjulian]

Has anyone had issues with a new rear brake compensator locking up the rear calipers? New brake lines(rubber and hard), new master cylinder, new calipers, new e-brake cable. System has been working great for 6 months. All the sudden last week while driving both rear calipers locked up. Pedal pressure was though the roof. Fronts still worked fine. Pulled over and let the brakes cool down and all the sudden they freed up. No more issues for the rest of the drive. Seems it has the be the compensator or master cylinder. I can't imagine that both pistons would stick and then release at exactly the same time. I have to think it is a fluid pressure issue. Any thoughts or tips would be greatly appreciated!!

[18Fiatsandcounting]

A couple questions:
- Were you applying the brakes when the rears locked up, or did they lock up by themselves?
- Did you replace the center rubber hose to the rear brakes, along with the 4 hoses to the calipers?

If the center hose is new, then yes, it does sound like the compensator / regulator may be bad. Sometimes I hear about front brakes locking up and it ends up being the master cylinder, but since it's your rears that are locking up, I'm thinking it's not the master cylinder.

And, just to be sure, there's nothing preventing the brake pedal from coming up to its fully "off" position? And the emergency brake cable is adjusted so that it allows the rears to release fully when it's off?

-Bryan

[ORFORD2004]

Next time it happen, unbolt the master cylinder from the booster a bit and check if the brake release. If they do, your booster rod is a bit too long (1/2 turn in).