I just got this 1995 Heritage Softail and I'm replacing the completely worn out rear pads, but cannot get the brake caliper piston to compress. I've removed the front reservoir cover, opened the rear caliper bleeder valve and with using a screw clamp, still can't get the piston to budge. The caliper bleeds OK when tested. I'm about to try removing the brake line, opening the bleeder valve and try again. Any suggestions? Is it possible the piston is frozen and the caliper needs to be rebuilt? I've never encountered a situation like this where the piston won't compress. The rear brake worked OK on the 50 mile ride home and didn't drag and it bleeds OK, but I'm stumped.

 

Easier to wrassle with it if you take the caliper off.

 

Shouldn't have to open the bleeder just remove reservoir cap and press slowly.

 

Agreed and done, but no success. Bike was ridden very little (5K) by prior owner over past 12 years, yet pads nearly gone, so wondering if piston being extended so long has frozen or corroded in place. May disconnect brake line next so I can get caliper on a bench. Any tips on disassembly if it comes to that?

 

If you cannot compress it then yes you will have to rebuild it. Kits are only around $14. Remove the caliper from the mount and hang it over a drain pan and use the brake master cylinder to push out the piston....

 

I use my air compressor to pop them out.

 

Not every one has a compressor...

 

Odds are if he can't compress the piston with a c-clamp it won't come out with air pressure.. however take care not do damage the piston.

 

I'd assume the piston is stuffed anyway. Just replace it, along with replacing all the caliper seals. I'd go ahead and throw a rebuild kit in the master cylinder also, and replace the brake line.

 

Whether you use air or the hydraulic system to pop out the piston, put a rag where the caliper goes and keep all body parts out of the brake.