What's missing?

[FutZ]

So i poped the top on the ol' Master Cyl and low and behold behind 4 screws and some black plastic...


Nothing.


Two holes and some fluid. Isn't there supposed to be a diaphram and a piston of some kind that I should unseat by squeezing the break to hard while bleading??? Am I just not looking deep enough but nothing else seems to want to come off? Does anyone have a picture or a good explanation they could share.

Thanks,

-FutZ

[prometheus578]

The bushings and the piston, etc are underneath that. If you haven't already, remove the master cylinder from the handle bars. Take out the pivot bolt and remove the brake lever. Now you can see the end of the piston. There is a rubber boot/sleeve covering the end of it, this you must take out. Work it offa the end of the piston and just pull it out. If I'm not sadly mishapen, there's next a snapring that has to go... Stick a snapring pliers in there, squeeze, and pull it out. Everything else will follow.

[FutZ]

Well that makes more sence... the book made it sound like there should have been more right there... I thought it was odd that I couldn't find a piston but it was moving the fluid with the squeeze of the break.

Thanks a bunch,

-FutZ

[pgg]

Hey Futz was there no black rubber under the lid.

[FutZ]

not unless it was stuck to it and I didn't notice...?

-FutZ

[prometheus578]

FutZ, Under the aluminum lid to the master cylinder there should be a rubber gasket/diaphram thingie (now THAT'S a technical term!) This seals the resevoir and keeps brake fluid from seeping out. It also expands/telescopes downward into the brake fluid to take up space as the brake pads wear and fluid fills more of the calipers. The idea behind that being to keep the resevoir filled with fluid without having an air pocket in there. With air in there, you'd run a chance of sucking air into the brake system should you apply the brakes, say while cornering, if the brake fluid sloshed to one side, thus uncovering the feed hole or relief port. Hhhmmm.... Speaking of feedholes... time for breakfast.