i've stripped my calipers down on my new toy.all 12 pistons are badly rusted and pitted,but 11 of them popped out fine with the air line,there's always one stubborn one tho isn't there.its stuck so well it wont even go back in with a 6inch vice and the seals are passing so cant get anyforce from behind.i've rigged it up to a grease gun(dont laugh,we've blown 3ft bearings off in work with one when the hydraulics leakpast the journal)and the grease just passed.new caliper job? I really dont want to spend on it,will roasting it damage the cast?dont want to find it cracking at the wrong time

How far out is it? Has it got cocked over and jammed itself? It doesn't need much to jam them. If so the only way is to push it back square.
Can you get grips on it and try twisting? That sometimes helps. Or try warming it, although I'd avoid the welding torch! Hot water maybe.

adrian

put the other pistons ins, block of wood to keep them in so only the one piston is able to move - the one oposite held with clamp and then then air line.

is it not moving at all - push it in then try the above.

weird coz

thanks for the suggestions,but i've tried them!it appears square,isn't far enough out to get hold of either,but when it wont go back in a vice i doubt anything'd pull it out.have to get a replacement which is a blow cause i was hoping to go and rip a quarry to pieces in the thing tomorrow!