Re: Rear brake still sticking after servicing.
 

Wow, crazy. TBH I haven't read the whole thread. When the caliper is off the bike, can you pump the lever and see the piston retract even a slight bit? And does the piston move back with assistance easily? Wondering if a seal might be on the wrong side out or something? Long shot, but might be the case.

Re: Rear brake still sticking after servicing.
 

As far as I know the seals fitted were square. Should they be tapered, and if so which way out?

Re: Rear brake still sticking after servicing.
 

Lumpy ridge facing outwards, flat surface sits in the groove

Re: Rear brake still sticking after servicing.
 

I will check the caliper I removed...

Re: Rear brake still sticking after servicing.
 

Cool, fingers crossed!

Re: Rear brake still sticking after servicing.
 

Seals on the problematic caliper that I removed look square. When fitted they do have a ridge which sits slightly proud on the inside. This made me think it was the wrong way around, so I flipped it and the ridge is still on the inside. Something to do with the seal recess? The seal definitely looks square when removed. I've cleaned the inside of the caliper and seal recesses when I fitted the new seals and piston a few months ago.

Re: Rear brake still sticking after servicing.
 

Tbh it's been so long since I cleaned a set of 650 calipers (front and rear) that I can't remember it the outer seal has the ridge or not. I imagine it does as the caliper serves no different function to the fronts, really.

I'd it a sliding caliper like the fronts, or a solid unit? Maybe the sliding pin is fudged. All seems really odd this!

Re: Rear brake still sticking after servicing.
 

It's working fine now with the original fixed caliper back on there, and that's using the pins from the one that wasn't. Process of elimination suggests there must be a problem with the caliper. Be good to say what though in case it can help problem solve for others in the future. For now my only fix has been to put my old caliper back on with the mounting thread recut straight (the reason it was removed and replaced originally).

Re: Rear brake still sticking after servicing.
 

i'll put it down to the new SS piston, it might be slightly bigger than the OEM one.

Re: Rear brake still sticking after servicing.
 

This had crossed my mind too. I've kept the original piston in the caliper that's fitted and working. The way to find out would to be put the SS piston into the caliper that's currently working and see if it stops working. Not something I'm going to do right now having swapped it all about several times the last few days. Maybe next time I change the seals.


The SS piston was easy enough to push back in by hand though. Similar in feel to the original. Tolerances must be fairly fine on them though.