STUCK CALIPER PISTON

Jesus wept - trying to remove stuck caliper piston out of tokico six pot - even using piston slide hammer tool to do it and no f*cking joy.

MOT tomorrow as well!

What’s my best option? Stick it back on the bike and try and squeeze it out with the brake lever*?

*I did this when it was on the bike and it didn’t move then!

F8cking p1ssed off.

Many thanks any advice.

could try wedging something between all the free pistons and using master cylinder pressure on the bike so all the force is directed at the one stuck piston?

i assume you left it in penetrating oil right. ive heard air pressure is good - but doubt you have access to it

Use a piece of old brake hose, attach it to the caliper then blast air down it

Or you could use a grease gun to pump grease into the caliper to force the piston out…

Or use my genius method as photographed in my ‘quiz for the spanner heads’ thread, but that might not work if it’s totally stuck and you can’t get any rotation on it

I took a caliper to my local Kwik-Fit and got them to blast the piston out for me using one of their compressors. Do you have any sort of friendly car/bike workshop near you that might be able to do the same?
Just be sure to wrap a rag round it first so it doesn’t go flying across the workshop :Whistling:

Thanks for the suggestion guys - I’m gonna try the compressed air option - actually did this with a footpump once - if that doesn’t work i’ll stick it back on the bike and try fluid pressure.

I’m officially having a mare here . . .

if you have transport, pop down with the caliper and il knock it out for you :slight_smile:

Thanks Matt - I would be round yours in five seconds - I’m so desparate to sort this thing - but I’m outside London :frowning: - (I just work in the smoke).

The compressed air isn’t practical at the moment - so i’ll reassemble and try fluid pressure while clamping up with a bit of wood the pistons that are moving.

F*ck it - I’m gonna have to take it to a shop - two pistons are utterly frozen.

Frozen you say? You could try that. I mean freezing it, or in fact heating it. The pistons are likely to be a different metal to the caliper and a change it heat will cause one to shrink (or expand) more than the other, thus freeing them up. Might be worth sticking them in a bag in the freezer for a few hours/overnight, or heating them with something, if you can’t get to a shop today…

*** make sure you don’t get any brake fluid on your food; it’s carcinogenic! ***

Hydraulic pressure has always worked for me. Plenty of penetrating oil around it first. I have occasionally had cause to wedge two spanners in the piston and get some twist on it. :slight_smile:

Thanks Cjkit/Scorch - i’m gonna go for hydraulic pressure tonight - cable tie some blocks of wood in to cover the working pistons and see if the frozen ones will pop out under pressure.

Wish me luck!

Are you being savage enough with that slide hammer ? It very hard to fail with a savage use of a slide hammer :smiley:

Totally - I’ve got this draper piston extractor slide hammer thing - has always worked for me until now - but I only get about 5 0r six full force slides and the thing just pops out of the piston . . . about three of them are well and truly stuck.

I think the problem started when I stuck some new calipers in yesterday - had to force the pistons in to accomodate the new thicker calipers.

Bike hardly moved then - it was like the brakes were on - I thought fck it - i’ll ride it and free them up simply by wearing away excess brake pad - anyways - the calipers just heated up like fck and got red hot because of the resistance.

So basicallly I think that I’ve welded the f*ckers in place . . . :frowning:

What i should have done was overhauled the calipers before I put the new pads in - they are tokicos after all . . . :doze:

If they aint moving with big slide smashes … thats very very stuck indeed . You may have achieved fusion with the alloy . Does one of the 2 calipers work ? remove one disc , attatch working caliper . remove other hose blank it off . If it passes on one disc on the brake tester and only has one disc and one caliper ,I dont see why it would fail … Maybe ??? Then repair/ replace at your leisure .

Bloody hell - I hope I haven’t fused the thing . . . :frowning:

Thanks for the advice - one caliper has two stuck pistons the other one.

I’ll try with hydraulic pressure . . .

Its well jammed thats for sure . I never had the slide hammer defeated yet .

Oh bollocks - just want to get rid of the thing . . .

Is it true that 1200 bandit calipers will bolt straight onto the zx7r?

THE 4 POT NISSINS?

I have no idea . You know where there is one you can measure up ?