My rear brake caliper piston is super stuck in the caliper. It's sunk quite far in and without even a millimeter protruding to be able to pull it out. I know you can reconnect the brake cable and try to use the brake peddle to pop it out but it doesn't seem to work. I've heard about heating the caliper and not the piston and then trying to pump it out but this has not worked either! I've hear mention of using a foot pump but I cannot work out how to connect the pump to the caliper! Can anyone help??

My rear brake caliper piston is super stuck in the caliper. It's sunk quite far in and without even a millimeter protruding to be able to pull it out. I know you can reconnect the brake cable and try to use the brake peddle to pop it out but it doesn't seem to work. I've heard about heating the caliper and not the piston and then trying to pump it out but this has not worked either! I've hear mention of using a foot pump but I cannot work out how to connect the pump to the caliper! Can anyone help??

Have you a grease gun,,, if so put it on and that might pump it out.

Is the piston straight in the caliper? if not it could be wedged on one side not letting it push out.

EDIT : you have opened the nipple havent you !!!

I ended up having to drill it out! I took it to a motorbike shop who said they tried using a pneumatic pump and it wouldn't budge. I drilled a small hole in the centre of the piston and enlarged it bit by bit. When the hole was big enough I tried to prize out the piston. I broke a drill bit and a screwdriver but could still not prize it out or budge it a little. I could see one of the rubber seals/washers had come out of place and been jammed back in the tiny gap between the piston/chamber. The only way I could heat or remove the rubber without heating the whole section of the caliper was to drill a few times into the piston base - heating it up immensely. Eventually the rubber heated/melted and the piston actually rotated out of the chamber as I removed the drill. Finally! :-) Just need a new piston now...

I ended up having to drill it out! I took it to a motorbike shop who said they tried using a pneumatic pump and it wouldn't budge. I drilled a small hole in the centre of the piston and enlarged it bit by bit. When the hole was big enough I tried to prize out the piston. I broke a drill bit and a screwdriver but could still not prize it out or budge it a little. I could see one of the rubber seals/washers had come out of place and been jammed back in the tiny gap between the piston/chamber. The only way I could heat or remove the rubber without heating the whole section of the caliper was to drill a few times into the piston base - heating it up immensely. Eventually the rubber heated/melted and the piston actually rotated out of the chamber as I removed the drill. Finally! :-) Just need a new piston now...

There ya go, been looking for one myself

YAMAHA DT125R DT125RE DT 125 BRAKE CALIPER PISTON KIT £19.95

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=270747224894&ssPageName=STRK:MEWAX:IT

Hi mate thanks. Did see that one but mine was actually this one...

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=380297831020&ssPageName=ADME:X:RTQ:GB:1123#ht_500wt_717

you might not be able to see it as I bought the only one! Just re-fitting mine now - fingers X'd!

Could you possibly have a look at my new post titled: DT125R - HELP! Brake Fluid not draining from Reservoi...

Thought you may be able to help?! Thanks