As I drive my car, the front right caliper does not disengage from the rotor. The car shakes a good deal when this occurs. It is a fun fun ride when that happens. The only way I can get the caliper off the rotor is I crack the brake line and let out some pressure. Then my brakes are good again for a while. After I drive the car and use the brake the brake pedal gets harder and harder to push in. At first I thought I had a bad caliper on the front right tire. I replaced that and the problem still occurs. I looked at the brake hoses in the front right wheel well and they all seem hard, meaning I cannot press on them to pinch them, to check if they are going soft. I've checked the front left tire too, and that one does not have any problems that I can tell. I guess I'm curious if the master cylinder would need to be replaced or if it is the booster? Not really sure how to trouble shoot either one. I just figure the master cylinder from reading other posts and that is what my clymer's book says. Just looking for any insight. Thank you.

 

From your description, pressure is trapped in the brake line causing the caliper piston to extend and drag hard on rotor. You will need to check to find where pressure is trapped. I would start by cracking the RF brake line at the body side of the wheel flexible jumper hose. If there's no pressure there, the trap must be in the hose. I've heard of hose developing a loose flap of rubber that forms a check valve to trap pressure in the caliper cylinder. Hopefully, that's your problem.

If you have pressure at body side of flexible jumper hose, then next check would be where RF brake line connects to equalizing valve. Perhaps debris or faulty equalizing valve might trap pressure in only RF brake. It's unlikely to be above the equalizing valve (Master Cylinder) or all 4 wheels would have trapped pressure.

good luck

 

Not very common, but I've heard of brake hoses coming apart on the INSIDE. Debris can make it act like a check-valve, causing that one brake to remain applied.

Normally I'd say check the caliper slide pins, but they're new, right?

Have you replaced the brake master cylinder? Adjusted pedal height? The position of the piston must be correct when you release the brake pedal, otherwise the MC won't release the brakes properly. Incorrect adjustment of pedal height can cause that. If that's it, it should affect both brakes on the same circuit, diagonally opposite, so that's R-F & L-R.

 

The caliper and pins are new for the front right side. I'll have to check next time it occurs how warm each side of the front is. I thought I did that and the right side was on fire and the left was like the back two, but I need to double check that. But if that is the case, and only one tire is locking up, then it is probably either the hoses or the equalizer valve that could be blocking it up?

I have never done anything to the brake master cylinder.

 

Yeah, I think so.

 

bake master should make all the wheels lock up ,, i have never seen a brake master lock up only 1 wheel

A bad booster would give you a hard pedal but it should not lock up the wheels

i have yet to see a proportioning valve cause such an issue

But i have seen more than once a brake hose ( from caliper to metal line ) cause this issue , they crimp right where they mount on the frt strut