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View Full Version : Sure fire tips to remove seized caliper pistons?



Saul
07-19-2009, 03:34 PM
Rebuilding some breake calipers which have/had been sitting outside for too many years. I've got everything broken down now and cleaned up nice but I am stuck on getting the pistons out of the caliper housing. Need to get them out to clean up and clean inside then silicone grease and should be good as new.

I tried blasting compressed air in there to 'pop' them free but no dice as of yet.

250rAL
07-19-2009, 03:42 PM
Hook it up to a brake line and use hydraulic pressure. If it has two pistons, the one that comes out first has to be held in place with a c-clamp just before it's all the way out.

Saul
07-19-2009, 03:48 PM
Hook it up to a brake line and use hydraulic pressure. If it has two pistons, the one that comes out first has to be held in place with a c-clamp just before it's all the way out.

Yeah - that looks to be my next step.

Billy Golightly
07-19-2009, 04:15 PM
I have a grease zert brazed onto a banjo fitting. Bolt it down and pump with grease. works everytime.

Saul
07-19-2009, 05:01 PM
I have a grease zert brazed onto a banjo fitting. Bolt it down and pump with grease. works everytime.

Billy - I've been reading about this method too! Can you actually buy a fitting that will work with a grease gun and the banjo bolt hole threads or does it have to be custom made?

If only custom made - do you have any spares kicking around? :naughty:

Billy Golightly
07-19-2009, 05:19 PM
I've never seen them already made up, not saying they arent, just haven't seen any. If they are out there knowing how the markup on stuff is, it probably costs $50. Make one yourself, junk brake line, free, grease zert $0.60, about $1.50's worth of oxygen, acetylene, and brazing rod. I guess I could make you one if you really wanted.

Dirtcrasher
07-19-2009, 06:00 PM
If you merely unscrew the end of your grease gun (unless it's a garbage gun) a bit (where the 3 fingers are), then you can jam it on the bleeder, retighten it and force out the piston like chicken.....

Of course you'll have to be creative with whatever other bores or threaded holes are still open but thats nothing, if you have a surplus of goodies that is..... What are banjo bolts anyhow? 10MMx1.0 or something? Thats why I save any odd pitched bolt I run into, it always pays me back :D

honda250sx
07-20-2009, 11:51 AM
Saul. Here is how I do things. For a tri-z but all the same principles.

http://www.3wheelerworldforums.com/showthread.php?t=91986

SeaBass8
07-20-2009, 02:34 PM
^Edg-ima-cation right there!

Saul
07-20-2009, 04:51 PM
Saul. Here is how I do things. For a tri-z but all the same principles.

http://www.3wheelerworldforums.com/showthread.php?t=91986

VERY good thread/write-up - I got lucky today, went to purchase a new pistol type grease gun, got home and the the thing threaded right in the banjo bolt threads!! Popped the pistons out like butter.

Now to re-clean and reassemble!

Thanks all for tips!

rdlsz24
07-22-2011, 10:52 AM
I found this thread so I gave the grease trick a try on the stuck pistons on my 250R rear caliper... compressed air wasn't budging them. The grease got them right out. The only downside is having to clean up the mess of grease from inside the caliper!

Rob

Billy Golightly
07-22-2011, 02:18 PM
I found this thread so I gave the grease trick a try on the stuck pistons on my 250R rear caliper... compressed air wasn't budging them. The grease got them right out. The only downside is having to clean up the mess of grease from inside the caliper!

Rob

I left it in mine...I figured it was a good lubricant, lol.

aldochina
07-23-2011, 01:00 AM
i didnt think of the grease gun idea. the compressed air method is a joke unless its a working system. on the rear 350x ones i have done i just used a vice and pressed it out with a small deep well socket that was the right size to pass through small hole under the e brake mech. hardest part was getting the caliper square in the vise.