Topic: Master Cylandir leaking

[78_SaltLick]

Thanks again guys for your help. I really really appreciate it. You have saved me from having to either spend alot of time and money on repairs at a shop, or just basically have it sit in my garage. So thanks again for any help. Here goes with another question:

I dont think i spelled Cylandir right....anyways brake fluid is leaking out of the top of my master cylandir, it seems to be coming from the cap. Whenever i squeeze the brake handle, brake fluid will start running down the side of the master cylandir(coming from up inside the cap) by the end of the day, ive lost quite an amount of fluid, so much i have to replace it daily.  My question is this....i know its a faulty seal, or cap because once i top it off again, and screw the cap back down the fluid will run all down the sides of the cylandir, letting me know the seal isnt doing its job. that rubber seal inside the cap is bad, heck its 30 years old....can these rubber seals be replaced....are these rubber "seals" still used on bikes today? Is this something i can order from the local honda shop, Or is this something i will have to go dumpster diving for in a salvage yard?

[eldar]

There was a previous topic on this issue. There are three things to look at. The cap, rubber diaphram, and there is a plastic ring. I think the plastic ring sits inside the cap and that is actually what pushes against the rubber to form a seal.

Pull the rubber from the cap and you should see this ring.

So check the rubber for cracks and tears and check the ring for cracks as well.

[Bob Wessner]

..once i top it off again, and screw the cap back down the fluid will run all down the sides of the cylandir

How much fluid are putting in there? Sounds like you may be overfilling if it starts to overflow just from screwing the cap on.

[eldar]

Never thought of that. There is a line engraved into the side of the master. You should fill to this line.

[78_SaltLick]

Well, since this is on clubman bars, the cylandir is tilted kinda sideways, it doesnt matter though, i can tilt the handlebars so the cylandir is level, and when i add fluid up to the line, and screw on the cap fluid leaks out of the top. I do see that there is a line, and havent filled it over that. I thought the same thing.....this shouldnt be doing this if im only filling it up to the line, leak or no leak.

[eldar]

Ok if you are not overfilling then inspect the rubber and plastic ring. The problem is most likely there.

[78_SaltLick]

is the diaphram and ring something that can be purchased at your local honda shop? Im sorry i dont know if modern cycles use a master cylandir now or not, or if they all basically are the same, or if you can just go buy a new cap with the rubber in it or not.

[eldar]

You may be able to get them at a dealer. I have not had mine go out so I am not sure. Have you found damage to either part?

[eldar]

look in this topic.

http://www.sohc4.us/forums/index.php?topic=545.0

[78_SaltLick]

Duh!! Man i should have done a search first. Sorry guys. And thanks alot Elder for the re-direction to that thread. Its exactly the info i needed. Guess you can buy that stuff at your local shop. This place kicks butt!!  Thanks alot guys!!

dave

[TwoTired]

Just a heads up.
If the brake fluid is leaking into the switch control casting it will attack the plastic of the starter button/ switch contained therein. Eventually it will disintegrate, then no starter and no headlight.

If you suspect brake fluid has gotten in there, take the switch group apart and flush it with alcohol.

Good luck,

[78_SaltLick]

Dang man brake fluid kills everything it sounds like. Stuff is worse than acid.