brake piston how to remove it

[davexs400]

guys need advise got a front brake caliber problem i converted my xs400 1980 model aussie issue (last of points here ) and have fitted yamaha 1973 tx650 front end on my bike got pinned cut and machined to suit my tappered xs400 bearing et c works great forks i use a 34mm instead of 33mm xs400 , got a set of 6 inch over ready to replace standard i fitted for registration here . now my caliber needs rebuild twin piston i have torn it down but the piston either side it in pretty solid how do i remove without destroying the pistons , i have made a attemp by soaking them in a ice scream container with boiling hotwater and viniger after i used air to clear all air pockets in caliber , lets see if i frees up that way or any other idears that would work
thanks in advance

 

[drewpy]

I gripped mine (after taking off the rubber boots) with thin mole grips and turned clockwise and anticlockwise a few times whilst pulling.

 

[davexs400]

g'day yes i did my bake brake caliber that way and got it out but the twin front one is a tricky bugger becuase its a yamaha tx650 1973 one and has a piston either side of the caliber and cannot get multi plieres on it seen people are using grease gun pumping it into caliber to hydrolically force it out maybe might work , thanks for help
cheers

 

[volcomskater77]

WD40, PB blaster and large pliers and twisting motion should help.

 

[davexs400]

yes the xs400 brakes are easier to remove piston i got the rear one done and i had a old spare front one and freed it up in boiling hot water and vinger it cleans them and removes rust too the tx650 cannot get a tool on to it so buying xsmikes replacement china special tx650 1972-76 front brake caliber complete with pads for $70 plus postage best option

 

[Scorpio1963]

yes the xs400 brakes are easier to remove piston i got the rear one done and i had a old spare front one and freed it up in boiling hot water and vinger it cleans them and removes rust too

I hope this method works cause I have tryed pb blaster and gripping with a rag and visegrips so far its still stuck.So I shall see shortly.

 

[Scorpio1963]

Im going to let it boil for an hour if to say this method doesnt work can I use a propain torch to heat it up without damaging anything?

 

[jayel]

if the master cylinder works just pump them out with brake fluid, once one side starts moving clamp it down so it can't move and get the other side to move, working back and forth you can get both sides out far enough to easily pull out, brake fluid is a lot easier to clean up after than grease

 

[Scorpio1963]

Its already been taken off the bike,I tryed to compress it which doesnt happenI boiled for an hour in viniger which didnt work.I have it soaking with liquid wrench right now and Im going to let it sit overnight before trying again.It doesnt help that I dont have a bench vise but i did try holding it with c clamp and wrap a cloth around the piston then used a pipe wrench to try and turn it.No luck so if it sitting with the lube in all night doesnt free it Im going to try heat tomorrow.

 

[jayel]

the trouble with using pliers, pipe wrenches ect. is you screw up the pucks then you're looking for replacements, doesn't matter if the calipher is loose off the bike it will still pump out the pucks

 

[ECP89]

Mine was rusted pretty bad in the caliper. I tried soaking it in lube overnight, heating it, wiggling back and forth with pliers... nothing worked. My old man took one look at it, said; "thread a grease nipple in the bleeder hole, and pump it out with the grease gun." Took all of 5 seconds to pop it off after that. The power of hydraulics!

Good luck.

 

[Scorpio1963]

the trouble with using pliers, pipe wrenches ect. is you screw up the pucks then you're looking for replacements, doesn't matter if the calipher is loose off the bike it will still pump out the pucks

Exactly I dont want to screw this thing up.

The grease gun trick sounds like a sure bet If i cant get it out any other way I`ll try it.
Thanks for the suggestions.

 

[Scorpio1963]

Well tryed the grease gun trick that didnt work then the grease gun got stuck on the bleader screw nipple.After finaly getting that off.I though maybe some high powered air pressure would do the trick.so I tightened the bleader screw up,losed the other bolt and took it out.Pumped up the air compresser stuck the blow gun in the hole that the other bolt came out.Walla pop out it came.Thing is the piston isnt even corred it looks like new.So now should I replace the oring inside the caliper and how do I get the piston back in without damaging it?Nevermind Im smarter than i think I am.I cleaned out the grove from the oring.stuck a little grease or liquid wrench iside,then flipped the oring inside out and stuck it in.I took the piston got it started in the hole then use a flat a board and c clamp after lubing the piston and pressed it back in.

 

[jayel]

Well tryed the grease gun trick that didnt work then the grease gun got stuck on the bleader screw nipple.After finaly getting that off.I though maybe some high powered air pressure would do the trick.so I tightened the bleader screw up,losed the other bolt and took it out.Pumped up the air compresser stuck the blow gun in the hole that the other bolt came out.Walla pop out it came.Thing is the piston isnt even corred it looks like new.So now should I replace the oring inside the caliper and how do I get the piston back in without damaging it?Nevermind Im smarter than i think I am.I cleaned out the grove from the oring.stuck a little grease or liquid wrench iside,then flipped the oring inside out and stuck it in.I took the piston got it started in the hole then use a flat a board and c clamp after lubing the piston and pressed it back in.

take it back apart and clean that out grease or oil, can swell those orings locking up the brake don't lube any internal brake parts with anything but brake fluid

 

[xschris]

Oil will f-up everything in a brake system. Brake fluid only!!

 

[Scorpio1963]

Done cleaned it and lube it with brake fluid thanks.

 

[ECP89]

That's weird... mine was in there good and the grease popped it right out. Anyway, good yours came out.

I was rebuilding and repainting my caliper anyway; so the grease inside was a non issue (got cleaned out), and was definitely the least damaging way of getting the piston out. But of course you have to clean every last bit of the grease out as said above for anyone reading this later.

 

[Scorpio1963]

Im actualy glad the air pressure worked instead of the grease gun trick.I hate cleaning that stuff up.

 

[XSLeo]

Using a grease gun you have to remove the bleeder and replace it with the right sized grease fitting.
Leo

 

[Scorpio1963]

Well Im going to tell on myself when I was using the grease gun I forgot to open up the bleeder screwThen i realised why it wasnt working.Anyway the idea of air presure came to mind which was cleaner and worked great.