Calipers not releasing

[BigWill]

When starting off from rest no problems, after braking a few times I get a judder (bit like un balanced wheels) on the steering as if the calipers are sticking on.If I park and leave for a few mins the car does not judder (it appears they have released) untill I have brake again a couple of times, I then turned onto the drive to park on a downward slope and the car will not roll as if the brakes are on.Has anybody any idea's please Brian.

[V Mad]

I think judder and sticking are different things. Judder could be that disks are distorting when hot.

Sticking, if your car is not used often could be partially sized calipers; try pushing the brake pads/pistons in fully and out a few times; or better still remove the pistons, and clean them up, then fit new seals. Sticking might also be a fault in the master cylinder or servo, or partially blocked brake hoses.

[DJT]

Brian,

One possibility is that one of the front flexi hoses is collapsing inside and preventing the quick return of fluid. After a short stop it drains back.

Other than that it could be a sticky piston.

Dave

[brian0443]

Brian
Just had something similar with my brother's Maxi. Traced it to the servo not releasing pressure. The clue was that all brakes were holding on so it had to be in the master cylinder or servo.
Brian

[martin]

Hi Brian, just to add a bit to the above, if the caliper seals are old and worn, they let the piston past but not back, they're supposed to distort, then ease the piston back as they reshape, this could also explain the judder. I'm with Chris, kits including new pistons and seals are affordable and make it a once only job, while you're at it, replace the front hoses, stainless braided are the best. Cheers, Martin.

[BigWill]

I can confirm that there are new calipers fitted when this first started and the hoses are of the new braided metal type. I intially though that it was calipers so that is why I changed them and as part of the rebuild braided hoses were fitted.

[mike@thenook]

Are you sure it is the front brakes causing the problem and not the rears?
If the rear brake adjusters/lever arms are worn and sticking (a common problem) this will stop the shoes releasing sometimes. You can check by pulling on either side of the handbrake cable (with the car on flat and brakes "stuck") at the levers on each drum (handbrake off of course) - if it release then that is the problem.
I rebuilt mine and not a problem since and handbrake works perfectly.
Good luck,

[Ian Durrant]

Did you use Silicon Brake fluid? I have heard of the brakes sticking on when hot when using this. No idea why it should happen though.