R1150gs adv. Rear brake calliper sticking.

[san3]

Hi all, I'm new to site so please be gentle.I've a problem with the rear brembo caliper on my '03 R1150gs Adv. It keeps pushing out pistons and not allowing them return.Ive overhauled the caliper with new seals and bled system properly.It's an ABS model. Anyone ever have same problem or have a solution I would be grateful.
Thanks, John.

 

[iletts]

do you mean pistons not returning or caliper body not returning? pistons are retracted by the seals themselves, and do not usually give problems unless seized. The caliper guide pins are the usual suspects if the caliper isn't free to float. both pins, caliper bore and rubber thingy need to be thouroughly cleaned out and a smidge of grease applied on reassembly, I use ht silicon grease which i reckon is best, but others may disagree. even if the caliper is free, the rubber bellows will force the caliper outboard, so that the inner brake pad is always slightly rubbing on the disc, that's why it's a thicker pad when new. I clean mine every 6 months or so, half hour job. piston retraction can be checked by CAREFULLY applying a tad of brake and releasing with pads out, you should be able to see the pistons move back slightly when brake is released

 

[san3]

I mean the pistons will not return,they push back in by hand no problem.I have just fitted new seals and cleaned the whole caliper.The master cylinder seems to be working fine as well.

 

[Duchess]

John welcome to the site its good to have you with us.

I hope you dont mind but I'm going to move your post over tot he Technical section of the forum as this is more of the introduction/newbie area.

You should get a better response to your request there.

Hope you manage to get the problem sorted. Just a thought but have you tried to use our search facility? Type in a key word connected with the problem you need solving and it should direct you to all the threads and previous posts held in our archive section some of which may be of use to you.

Good luck and enjoy your stay with us.

 

[ELIMINATOR]

If you can push the pistons back by hand, then it would seem as the other person wrote earlier that the sliding caliper, isn't sliding. If you grab the caliper, and twist /tug / rock it, there should be some free movement. Have you got this? If not then the sliding pins may be corodded, or "gunged up".

 

[Bronco Billy]

Don`t Know if this might be your problem......?

 

[Bronco Billy]

The pins on my slider were corroded and the Calliper wasn`t moving. This meant the pads were wearing unevenly. I replaced the calliper (Under warranty). If this is your problem then just clean the crud off, lube it and there you go.

 

[san3]

Thanks for all the help. I've cleaned and lubed the sliders and there moving fine, also the brake pad pin. It's as if brake fluid keeps pushing out pistons without pedal been pressed.Could it be ABS problem ?

 

[iletts]

if you have non servo brakes, then i would have said that was impossible, but if you have servo brakes then you need to have a severe look at the servo, which is beyond me. anyway, welcome to the site and the wonderful world of bmw!!!!!!