Removing Stubborn Brake Pistons - HELP!

[votejc]

Hello all.

I am overhauling my front calipers with new seals, pads, and a return to their rightful gold colour and have hit a snag. I have removed the calipers according to the Haines instructions but the pistons are stuck in the bores. When I pumped them out with the brake lever some moved a long way and others hardly moved, I have split the halves and given them a quick once over with fresh brake fluid to try to ease them and still no joy. Only one of the pistons has come out of it's bore.

I have put the two halves back together and run a compressor airline into the banjo bolt hole but only the piston that has come out already that I had to pop back in has come out again! Any ideas? I could clamp or ziptie that piston in place and try to free the other three?

HELP!

[mick.mh2racing]

If you can get one to move with a compressor I'd fashion some way of holding it in to see if the others move. Once they do hold them in too and carry on with the compressed air.
Once they're out a bit very carefully grip them and try to move them. Lots of penetrating oil and lots of persistence.

[Hadies]

Make sure you put something in between the pistons when using compressed air. They come out like bullets

[votejc]

Make sure you put something in between the pistons when using compressed air. They come out like bullets

Haha! Almost fell foul of this earlier. I did put something in the way but unfortunately it was my head. Just about managed to get out the way! I was doing it in the back of a Landrover which was running the compressor and I properly dented the roof as the piston shot upwards from the load bay.

"What the fuck was that bang?!"

"Nothing...."

[Hadies]

Haha lucky it wasn't your face. Also lucky it didn't hit your windows!

[Lane]

Some can be too old and seized to even budge with compressed air.

In the past i have fashioned up a small jig where you use a bolt with a rubber grommet close to the size of the inside of the piston, place two washers either side of the grommet and tighten it up until the rubber grommet expands and grips the inside of the piston.

Now use your socket over the bolt and twist the piston while applying pressure and it should come out.

Failing that, vice grips and a good rag, careful though!!!

[Sligeach]

Have you watched my video on youtube. Look in the workshop section. I would link it but i am posting from my mobile.

[Neosophist]

Yes hold them in with a ziptie.. put something in the piston to stop the others flying out too.. keep fingers well clear, you can actually break your fingertips off!

once the pistons move a bit you can pull them out

[Deviant400]

i used an anchor bolt http://cgi.ebay.co.uk/EYE-BOLTS-SLEEVE- ... 2eb5fb168e a bit like that , tighten it up enough to grip the inside of the piston, put a bar through the eye twist and pull , plop out they came

[Morespeedvicar]

i usually put a bit of angle iron in the middle of the cailper while its still complete and some wooden peg halfs to keep it there while i pump the pistons out, saves pumping pistons out against the disc. not the neatest method but it works tho.
Cheers
Ian