Topic: Stuck front brake piston

[stingray]

How do you remove it?  I have tried slowly pumping the brake lever to try and move it but no luck.  Should I still be able to get a hard lever with it removed from the caliper?
It is frozen man!

[Buffo]

yes you should get the same pressure on or off the fork...the piston is stuck in the caliper...

I would pump the crap out of the leaver...fast and complete pumps...

[mick750F]

   If you have a compressor you can try using air. You can also try a grease gun on the bleeder fitting. If you use air jam a rag in the caliper to keep the piston from flying out. And keep your fingers away from it.

Mike

[stingray]

I would pump the crap out of the leaver...fast and complete pumps...

Hey Buffo, so if the lever is spongy, then I have to do the bleed thing first....right?  Then it should harden up, even wit the caliper removed. 
If this trick doesn't work, what next?  The blast of air??

[Buffo]

you may have to bleed it if your not getting pressure build up...the compressed air works good too...

You may have to press the piston back into the caliper with a c-clamp to break it loose...I have heard of the grease gun method as well

[RCS1956]

I had the same trouble with mine, since it hadn't been used in 7 years. The local Bike Shop wouldn't work on anything over 10 years old, but they recommemded a welding shop that built chopper and racing frames. The welding shop drilled a pencil sized hole in the caliper housing, tapped out the piston, and weld sealed the hole and filed it so you couldn't see it had been drilled. I had to buy the new seal and clean out the old dried fluid but now it works fine. They charged me $40, but if you know a welder, it might be cheaper.

[hymodyne]

I used the grease gun method on a piston that had been frozen quite a while.The SAE threaded small hand gun can be threaded just enough into the metric caliper to make it work without ruining the threads. Popped it right out. Just be sure to do a good clean up aftewards, grease and brake parts not mixing well and all...

hym

[Bob Wessner]

I used the grease gun method on a piston that had been frozen quite a while.The SAE threaded small hand gun can be threaded just enough into the metric caliper to make it work without ruining the threads. Popped it right out.

I used the same method, worked like a champ. 

[Mark M]

Heat can also help to break the seal, a butane blow torch to get it nice and hot and a bucket of realy cold water to cool it quckly can help to break the corroded seal as the different materials will expand and contract at differing rates. Even just the heat on it's own works wonders for most siezed parts. Just dont touch while still hot, I always forget that bit!

[stingray]

All really good suggestions, thanks.  I'm going to try the compressing the puck with a clamp to see if I can move it, then try pumping more hydraulic fluid.  If no go then the grease trick and then heat if needed.  I'll let you know what worked.
Thanks!

[damn_yankee]

I did the grease gun method and it worked great. You don't want brake fluid spattering on the bike if you can avoid it - it eats paint.
When the piston finally came out it popped real loud and fast. I had it aimed against a piece of wood. Wear eye protection!

[stingray]

Piston out!  The grease gun method worked really well.  I used an air pressure grease gun and a couple of hits and first the puck fell out then the piston followed.  I got a little nervous cause the grease kept wanting to escape the threads, so I had to crank it tighter than I wanted.  The brake line was stubborn going back in but straightened it self out.
Now, how do I dress up the insides? It's not bad but has white residue all over.  The rubber seals seem in good shape.  Whats the best way to pull them out and try and salvage them?  Or is it not worth it.

[grumburg]

Grease gun worked for me. Can adjust amount of pressure needed. Took 5 minutes.

[BobbyR]

I tried everything including including feeding an industrial compressor directly into the caliper through a fitting. I had a C clamp positioned to ctach the piston. I tokokk it off and then hit it with a torch while feeding the air. Something sounding like a cherry bomb went off in the garage and the piston went 40 feet out the door and into the woods never to be seen again . Heat works, just put something in place to keep the piston from flying out, and keep your face away.

[bgfootball67]

So after doing a search and finding this thread, I was able to get my frozen caliper out using the grease gun method, thank you to everyone who contributed!  This is a board is awesome. 

What have you guys found works well to clean all of that grease out?  Any suggestions?  Any suggestions before I put it back together?

[jrrobertsjr]

I cleaned most of it out with a finger and then some paper towels.

Then I some carb cleaner to break the rest of it down and clear out the holes.

[BobbyR]

Denatured Alchohol will dissolve the grease and old brake fluid. It is the component of the brake fluid that absorbs water and also evaportes and leave the gunk. It should not harm anything.

[Black Hercules]

 Grease gun also worked for me as well, plus it's safer then using compressed air , if that piston comes flying out! it will  really hurt someone or yourself if you are not careful. Peace!! Raul, from long Island N.Y.C.

How do you remove it?  I have tried slowly pumping the brake lever to try and move it but no luck.  Should I still be able to get a hard lever with it removed from the caliper?
It is frozen man!