Softail Rear Brake Piston Won't Compress
Seasoned HDF Member
Joined: Apr 2011
Posts: 6,185
Likes: 2,134
From: W. Texas
A peice of wood does well in front of the piston when blowing it out wuth compressed air. And DO keep fingers out of the way.
Ya may want to consider replacement of the caliper if stuck that badly. Most likely will have lots of corrosion in there.
WP
Ya may want to consider replacement of the caliper if stuck that badly. Most likely will have lots of corrosion in there.
WP
Dirt don't hurt
Joined: Jan 2011
Posts: 21,065
Likes: 4,561
From: Haslet Texas
Dirt don't hurt
Joined: Jan 2011
Posts: 21,065
Likes: 4,561
From: Haslet Texas
If you get it from the dealership it's expensive but it also gives you a new piston and some grease for it.
Seasoned HDF Member
Joined: Jan 2011
Posts: 157,527
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From: Michigan 15 Minutes East Of Hell
Club Member
Joined: Aug 2008
Posts: 22,868
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From: Lafayette, Louisiana
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.
But seriously, on a bike that's that old and was sitting for that long, and on something as important as the brakes, and given that you can probably buy all the parts you need for under $100, and given that the bike is already "down"...hell yes I'd just do it all. Last thing I want to do is half-*** the job only to have to take it back apart later because I didn't whole-*** it in the first place.
Seasoned HDF Member
Joined: Jan 2011
Posts: 157,527
Likes: 57,084
From: Michigan 15 Minutes East Of Hell
I've gotta agree with Omaha ... Go through the system while it's down and ensure yourself of trouble free braking.
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Joe Kucinski
Ultimate HDF Member
Joined: May 2006
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From: Ohio
Speaking of spending money, it is possible that a frozen piston caused the pads to be so worn. That would have caused a lot of heat, so check out the rotor. Look for warpage and/or cracks. Good luck.
Stellar HDF Member
Joined: Jul 2014
Posts: 2,721
Likes: 243
From: NC
Prot makes a good point. OP the rear master cylinder is down by the rear brake pedal mounted on the frame. I know could just be terminology but if it's bleeding it should be moving. You say you are trying to compress it try some PB Blaster on it and let it sit with some pressure from the clamp on it. Definitely sounds like you will need to do a complete tear down on it if it is stuck.
Pull it all the way off the bike so you can work on it without the hose attached on your bench.
Pull it all the way off the bike so you can work on it without the hose attached on your bench.