Sticking calipers, how do I "unstick them"?!

[GOB]

My apologies for not being Porsche related :oops: , but I believe it should apply the same.

My Euro BMW M Coupe has the Euro floating rotors, ATE blue fluid (about a year old), and PBR Metal Master pads (5K miles on them) and until 4 days ago, it braked a lot better than my 996 C2. Well, I don't know how or why, in one relatively aggressive braking maneuver (115mph to 10mph) :drive: without invoking ABS, I did "something" that caused the discs to become blue (too much heat?!) and my pads to "swell up" to the point that it felt as if someone was lightly braking all the time. I have done the same thing before many times and it has never happened before. I did drive for about 15 minutes to cool them off and occassionaly tapping the pedal to see if they would "release back" and they did, but not fully. I parked it for a couple of days and now the same dragging caliper/brake applied all the time/ blue disc is back. It mostly concentrates on the front right corner, some on the left, nothing on the rear.

What should I do? Bleed the brakes? Sand down the pads? Any idea will greatly appreciated. :help: :help: :help:

[GOB]

Well, I found out that it basically concentrates only on the front right caliper. Removed it, sanded down the pads, bled that corner and it was all fine before lowering it to the ground. Went for a short drive and I could tell there was something "slowing" the car down. Sure enough, back into the shop, raised the front right and the wheel does not spin freely (it used to be that I could not get it to move even if I tried before doing all this). Mechanic said I need new caliper kit, but I am not so sure since all seals looked fine and not a drop of fluid anywhere.

Any ideas as to why the piston is not returning after releasing the brakes? I am off to bleed the rest of the calipers, but if anyone has any ideas, please do let me know!!

[rjf123]

Well, I found out that it basically concentrates only on the front right caliper. Removed it, sanded down the pads, bled that corner and it was all fine before lowering it to the ground. Went for a short drive and I could tell there was something "slowing" the car down. Sure enough, back into the shop, raised the front right and the wheel does not spin freely (it used to be that I could not get it to move even if I tried before doing all this). Mechanic said I need new caliper kit, but I am not so sure since all seals looked fine and not a drop of fluid anywhere.

Any ideas as to why the piston is not returning after releasing the brakes? I am off to bleed the rest of the calipers, but if anyone has any ideas, please do let me know!!

In my 996 the front caliper began to stick at about 100,000 miles. No fluid leak or signs of seal wear, just a single (only the outer on one caliper) burned up pad.

Rebuliding the monoblock calipers is not hard, and thus far has solved the problem. The kits cost $50 per caliper. It's a dirty job, but definitely doable.

[GOB]

Thanks. At least you confirmed for me the suspicion that in fact I do have to rebuild the caliper. Dang it! :censored:

[skyline]

I know this not very constructive but hit it with a hammer, My dad was ace & once fixed our telly with one. Seriously i have had this happen on a lot of cars, problem is usually 1 of 2 things. 1st the calipers on some cars are floating on pins so to speak so they can follow a cars braking caracter without seizing on. Sometimes dirt or corrosion gets on the pins & prevents movement. Clean & all is well. 2nd thing is the pistons stick in the caliper housing,, Partial seizure. Pull back the rubber boots & look for rust or dirt & remedy. Hope u sort it Cheers, Steve.

[Ubermensch]

As others have suggested you have a pretty classic problem: a sticking caliper. A rebuild is the solution (not a difficult proces on most calipers if you want to diy).

[GOB]

Thank you all. Need to get the rebuild kit in the States since the local stealer does not have it in inventory and wants about 5 times the normal price.