Rear brake caliper rebuild

[daveyg]

My rear brake caliper is seized up, and was wondering where i could get a rebuild kit, and also how to remove piston. I have already removed c-clip and can lift up the rubber boot, but i cannot pull the piston out. Any ideas/tricks?
Thanks alot fellas, Daveyg.

[rpgoerlich]

On one I soaked it in penetrating oil and used air pressure to push it out.
The other I soaked as well but ended up having to drill into the piston, insert a screw and used a slide hammer to pull it out.

[tarzan]

I had to reinstall the caliper,Just the hose.I didn't install on the rotor.Then just pump the brakes while keeping an eye on the fluid level in the master.If your rear master doesn't work, you can undo a line on the front and connect it to the front master.It will slowly push the piston out.
I did this last week on two different calipers that were froze up.

[GARTHXS]

what I did

soak over night with pb blaster then took a set of vise grips and locked em on the rim and put the caliper between my feet and pulled real hard, I also gave them a wack with a wooden dowel first to break them loose. Mine were sitting for ten years but did not require any new parts ,I just cleaned them up with a scotch brite pad and cleaned out the groove on the inside of the caliper and they seem to work fine now!

[xs11head]

On the really seized pistons, I heat the caliper/ piston area and then apply air pressure to the banjo bolt hole where the brake line attaches. Just remember to keep the piston face down or away from you, it will shoot out. Sounds a little crazy but works every time on the stubborn ones.

[xs11head]

Oh, partsnmore.com for the kit

[greatnw]

One of the best tips I've ever used was for this. Put a proper fitting bolt in the hole for the line. Put a grease gun on the bleeder and it will push the piston out. Took a pretty fair amount of pressure to break it loose. Then it slowly walks out. My piston was beyond saving but the caliper cleaned up nicely. Got a new one and a rebuild kit and it works great. Parts n more for all if I remember correctly. I'm thinking I might have picked up the piston from Mike's XS but can't remember for sure. It was about $20.
You can do it!

[crazy steve]

Just got done tearing down mine, so I feel your pain.....

If none of the above work pulling the frozen piston (and I tried 'em all), there's always the grease gun trick. This has NEVER failed to get 'em out.

But to make this work, you need a way to connect a zerk fitting. I used a spare banjo bolt but you can use any proper-sized Bolt (8mm I believe), drill a hole with a #3 bit through it, tap it with a 1/4-28 tap for the zerk, then screw the assembly into the caliper. Apply the gun, and out it'll come. A grease gun will develop hundreds, if not a thousand, lbs of pressure. Totally non-harmful to the parts, safe, and a LOT less work. It is a bit messy though...

'78E original owner

[bikerphil]

I recently used 2 screwdrivers to pry a caliper piston out. One screwdriver thru the brake pad lining inspection hole, and one on the other side of the piston. I used small blocks of wood to adjust the fulcrum points for prying. After soaking the piston with PB blaster for a half hour, it took about 5 minutes to pry it out.

[DGXSER]

I've used both the master cylinders and the compressed air method. If you use the compressed air method, make sure to put a rag between the piston and the caliper and make certain for sure and absolute that nothing you do not want in several pieces like your fingers is in the path of the piston. It will pop out of there like a bullet.

[redbone]

yes , compressed air never fails, but like dgsxer said put rag or piece of wood in there and make real sure NO FINGERS.

[daveyg]

Perfect! Thanks guys those ideas are all just exactly what I needed to hear! What comes with the mikesxs rebuild kit? Cuz the rubber is still in good shape...

[DGXSER]

For the rear caliper, the only thing you typically would consider replacing is the rubber o-ring inside the caliper. The outer rubber boot is a dust seal only.

If the piston is shot, you can get that at parts-n-more which was probably already stated.