Rear Brake Master

[AApple]

I finally located the persistent leak I have in the rear brake. The master is leaking/dripping onto the exhaust, and burning, which is why I have never seen any drips on the garage floor. As long as I don't let the reservoir go dry, the brake works fine. I have been having to bleed it when it goes dry. Anyway...now I have to locate a reliable kit to rebuild the dang thing. Any suggestions? I've seen so many post here about not getting the proper sized cups/seals, I a-skeerd to tear into it, for fear of not having the right components to fix it. Of course, once I get it off and torn down, there will be no way I can put it back with the old seals and it work, if I get the wrong stuff.
So....anyone have a definitive size on the bore, and where to get a kit that will be right, and also be of a good quality? :beg:

 

[joedrum]

oh boy

 

[mcgovern61]

I rebuilt my '81 rear master with the K&L rear master cylinder kit. I got it from Crescent Moon Cycles but Bike Bandit and others have it. Google K&L master cylinder rebuild kits. My works great, no leaks and easy to work with.