getting the second brake piston out?
 

dear all

After much fiddling and splilt brake fluid I have finally got the pistons out of my FZR calipers. Well I got one piston out of each..... how do I get the second one out without a compressor?? I got the first ones out by pumping them out with a spare front brake master cylinder. I could replace one side and then do the other by holding the first in with a clamp, but would rather get them both out so I know the caliper is spotlessly clean for a rebuild - any suggestions anyone?

A neat little trick is to use tyre irons - or something similar.

Place a bar between the irons

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then insert the irons into the cylinder

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Squeeze the top so that pressure is exerted inside the cylinder and then pull.

Get plenty of penetrating oil in there first. Works quite well if you're without a compressor.

Hope that helps.

m

I always push one almost out, just a few mm's in the caliper. Then clamp it and push the otherone out. The last mm's of the first piston I can get it out by hand.

rob

cheers
 

thanks for the tips, will dig those tyre irons out and give it a whirl...

I just had the same fight with 2 really old front calipers from an xtz 750. All four pistons were very much seized in place.

My recipe for removal was.

1.wait till the wifes out of the house for a few hours.

2. preheat oven to 180C

3. find an old oven tray

4. place afor mentioned caliper's onto tray

5. bake for 4 mins

6. remove from oven and free the pistons using vice grips.

I was renewing all the internals of the caliper's so wasnt to concerned about gouging/scratching the pistons or the fact that 2 seals melted.

Took minutes to remove once out of the oven. The previouse day I'd used about an hours worth of foul lanuage and shouting to no avail.

I've just cooked the sunday roast in the same oven. If i dont post again soon then you'll know It's a bad idea and may poison you..

Good luck.:thumbup1:

Get yourself a DOT3 or DOT4 brake fluid bottle whichever is the one for your brakes.....take the bleed screw out and when you compress the pistons some oil should come out or just unscrew the brake cables.... that should work....

the tyre-lever method works well. I use metal bicycle tyre levers, which seem to be the perfect size. but if you are still struggling, take the caliper to your friendliest bike shop, they'll have a very useful little tool that extracts the little gits out with no fuss/force.

Couldn't get the tyre levers out, so ended up taking one out, cleaning, putting old seals and piston back in, take other one out, clean, put new seals and piston in, clamp and replace 1st piston. Bit of a ballache - do the brake piston removing tools (such as the one by Sealey) work then Dougie? I will have to do this quite a lot so might invest in one!

hi,

yes, the piston removers do work. not sure about the Sealey one (only because I haven't seen it). I tend to end up with Kawasaki's which need a lot of brake caliper attention. So I'm thinking of getting one. When I get round to it I'm going to ask my local bike shop which brand they use.

cheers,
Doug

Dougie

let me know what the good stuff is! Have just gone through the manual for my latest project and it suggested splitting the caliper to overhaul the brake piston seals - sounds a bit off to me.... anyone split their calipers?

hmm... depends on your calipers. the last few I've done have been six-pistong tokico. and I normally gently push the pistons out with the caliper whole, so the pistons meet in the middle. Then split the caliper and pull the pistons out.

Not sure I understand how you'd get the piston out without splitting the caliper? I'm assuming an active piston either side of the caliper. I think an old GT550 caliper I once serviced only had a single active piston, and was a single cast item.

what's the Sealey tool, do you have a link?