Stuck brake piston

Have you tried these Luke?



What bike is it on?

[yorkie_chris]

Some dangers of the err interesting advice so far.
If you muller the piston with mole grips, which is inevitable, you can also distort the piston out of round which clamps it in good and proper.
If you apply penetrating oil you may swell the seals and clamp it in tighter.

If you are going to attack it with mechanical tools, wind a jubilee clip around the offending piston.

Hydraulic method is best and safest way (preferably BEFORE you split system!). If you can seal the passageways in the caliper, you can replace one piston, fill it with water and then use a G clamp to force that one in, so popping the other out.

If you are going to use some caliper removal tool the expanding mandrel type ones are brilliant, the actual plier type ones are ok but haven't really got the balls behind them to pull a proper stuck one.

put the other pistons back in,you may have to hold these in with a clamp or a vice and pump the stuck piston out with a grease gun,a air line will put out a 150psi, a grease gun about 10.000 psi and you cant compress grease so it has to move

Cheers for all the replies, I have a few things to try

Originally Posted by yorkie_chris

If you apply penetrating oil you may swell the seals and clamp it in tighter.

worked on the race callipers that i was working on, although they had no dust seals so that could affect the way it worked

[yorkie_chris]

Not saying it will never work, just pointing out the risk of it.

Originally Posted by yorkie_chris

Not saying it will never work, just pointing out the risk of it.

ohh right fair enough, the only thing we were told not to use is stuf like brake cleaner around the seals as they will blow them (yes you cant use brake cleaner on "brakes".... can use it on every thing else though )