Master Cylinder piston won't come out.

[Tarbash 27]

I hope you have both circlips out. One is for the rubber boot dust cover, that comes out easy. Then there's a snap ring underneath it. On mine, I just used a set of needle nose vice gribs to clamp onto the piston. I just yanked it out hard.

[almarconi]

I've done that in the past, but I don't think the design of this m/c will allow that. The bolt hole is on the bottom and the piston is on the side. Could you describe a little more please, if I'm misunderstanding you.

My comments were geared towards the L style master cylinder. After looking at the parts fiche for the G model this would not work.

I would try to soak the part, apply heat and continue to try and move the piston. Eventually it will come out.

[ThomasTedder]

I hope you have both circlips out. One is for the rubber boot dust cover, that comes out easy. Then there's a snap ring underneath it. On mine, I just used a set of needle nose vice gribs to clamp onto the piston. I just yanked it out hard.

Well if there's a second circlip in there, that could explain things. I looked, but maybe it's hiding under some rust.

[almarconi]

Well if there's a second circlip in there, that could explain things. I looked, but maybe it's hiding under some rust

What did the clip you removed look like?

The one that holds the boot on is a piece of wire shaped like a half circle



The one that hold the piston on looks similar to this..

[almarconi]

To remove the snap ring you need a pair of snap ring pliers with very long jaws or a machinists scribe. I used a scribe because I had one and didn't want to spend the money on the pliers.

[ThomasTedder]

What did the clip you removed look like?

The one that holds the boot on is a piece of wire shaped like a half circle



The one that hold the piston on looks similar to this..

That's the one I removed. I have a "special master cylinder tool" that I made. It's a fork with three of the legs bent down and one left straight. Works like a champ on CB's too.

Whew, glad I wasn't banging on it for no reason.

[almarconi]

Where you able to remove the piston?

[ThomasTedder]

Where you able to remove the piston?

No. It's still soaking in the Berrymans. I'll let you know.

[mike-s]

I had a master cyl rusted solid on my gsx250, using penetrene on it and topping it up each night for a week after removing the circlips didn't do a damned thing. Gave up after doing that, trying heat (couldnt use to much, given the res was plastic) didn't do a damned thing. Ended up with a master cyl from a gpx250 on there instead and it works fantastically (its all metal as well, im not a huge fan of plastic being used on the master cyl's)..

[ThomasTedder]

It's FREE!

The Berrymans and PB Blaster didn't do a damn thing. Neither did me and my brother playing tug-of-war. I drilled a hole and screwed a screw into the piston, then used a hammer to pry it out.










Thanks for the help.

[tkent02]

I was going to suggest hydraulic pressure, connect the cylinder up to the brake line to the rear caliper, then step on the brake.

[almarconi]

That is one ugly looking piston...how does the bore look?

[ThomasTedder]

That is one ugly looking piston...how does the bore look?

Not too good. Lots of rust. It's starting to clean up. I'm kind of worried that if I buy a new piston/cup it may not work.

[chef1366]

If there is rust in the bore you either need to hone or get a different one.
I like your ThomasTedder engineering.

[Suzuki_Don]

Yeah!! Nothing like a bit of LEVERAGE, ay Bill.