right front brake caliper won't release. WHY?

did you change the slide pins and lubricate them? I have had calipers hang up because of warped pins and brackets. Also, is the tire torqued evenly and are the caliper bolts both tight.

Jeff, thanks for your reply. I borrowed a factory service manual from the library. I will look at the car again tomorrow but I think that the 2 rear brake lines have been installed into the wrong ports on the master cylander. this is a diagonal system so I'm hoping that if I reverse the rear lines it will correct the problem. I think the items you brought up are all ok but I will double check them anyway.

a bad master cyl can also exibit these same symptoms, so if switching the lines doesnt help i'd look into it.

REPLACE THE RIGHT FRONT BRAKE HOSE...... they will allow fluid out of the master cylinder but not return... brake hoses break down over time and collapse internally.. about 99% sure this will fix it all for about 12 bucks and about 30 minutes of time. Mine did the same thing

the right front brake hose is more likelyto fail than a proportioning valve on the master to fail

Chris, you were right. the flex line was the problem.thank you to everyone who took the time to reply. Tom

I have a smiler issue. Even after replacing break pads,rotors, callipers hoses and master cylinder. still calliper is not getting released and the breaks pads are getting Jam with rotor and over heating. please advice.

the only thing left is to clean the spindle slide for where the caliper glides across make sure it is smooth top to bottom and use a little anti seize on it also.

I am having the same problem with my 98 Neon. I have changed the calipers, rotors, flex lines, master cylinder, proportion valves. It was okay for 2 months, it doing it again, HELP, the wheel gets so hot the hub cap melts off. I ordered caliper, rotor and brake line again. The brake booster is the only thing I have not changed. I will replace the booster and look very closely at the guide pins. Maybe the booster is not letting the master cylinder return the fluid.

Highly unlikely it is the booster. I would go over everything again push back caliper makr sure everything goes back easy slides freely. Make sure the bleeder screws are at the top, i have seen a lot of cases where people install the calipers on the wrong sides so they will not be able to bleed properly, also i have seen the parts store sell people two left or two right calipers so not being able to bleed one. Double check part numbers and stay away from rebuilt calipers. Hope that helps.

I am having the same issue. I replaced the caliper and rotor... Now I am going to replace the brake hose. THANKS. Never would have thought of the hose breaking down internally. I was about to change the master cylinder... On 2010 Toyota Corolla.