caliper not releasing

[meansho]

My right rear caliper does not release after letting off of break pedal. All parts are new on right rear wheel incuding brake hose and caliper as well as parking brake cable. Left rear wheel is free. What could cause this? LOOSENIMG BLEEDER FITTING RELEASES CALIPER.

 

[sperold]

It is a brake hose problem.
Sometimes they collapse internally. Other times, the bracket they are held with, rusts on the inside surface and squeezes the hose.
Your foot pressure can force the fluid past these blockages, but the return mechanism cannot.

 

[TimboSHO]

Make sure the parking brake cable returns all the way. If the hose and caliper are new, you need to find out why there is still pressure in that circuit. Does your car have ABS? I'm sure something could be sticking in the module. Does it stick every time you apply the brake?

 

[rubydist]

your symptoms are nearly always due to a brake line/hose problem as sperold has described. there is a small chance that the park brake cable could stick and cause the same symptoms, but only if the park brake has been used.

 

[jimtash]

It can also be the pins themselves. I recently had to deal with one of them being completely frozen which was due to the rear brakes not having to be messed with for years. Thankfully the caliper brackets are still available as remanufactured units.

 

[meansho]

the car does have abs. it happens everytime I hit the brake pedal. the module has been replaced as well as all the brake lines going into the hclu. I am stumped.

 

[Irish Pride]

Check your bias valve. It could be so corroded that its sticking. Bias plugs might be needed.

 

[luigisho]

I second the above as possible. I'm currently having issues with the bias valves and corrosion.

 

[itwonder]

My experience is it's likely a master cylinder problem. After chasing all of the things listed above, including replacing the RR caliper twice, it turned out to be the master cylinder, which was original on my car at 240K and 21 years of age. Way overdue. I replaced it with one of the new manufacture made in China ones; working great and price was reasonable. If you go that way notice that you have to reuse your old master cylinder to brake booster seal and reservoir.