leak after replacing master cylinder

My '70 bug has a brake fluid leak after I replaced the master cylinder. When I installed the new MC, the brakes were still not right. Since I was tired, I called it a day. When I started working on the car the next day, I found that all of the brake fluid had leaked out. From the looks of it, the fluid is leaking out near one of the two brake sensor switches. The switches were screwed on tightly, and the threads seemed to be the right size, so it didn't seem like there would be a problem. Obviously I did something wrong.

Here are my questions:

Is it possible that the fluid is actually leaking out through the switch itself? (It doesn't *look* like there's any place for fluid to leak out.)

Should I have used some kind of sealant on the threads of the switches - maybe teflon tape? It looks like there was some kind of white sealer on the threads, but none of the books I have (Chilton, Haynes, Muir) mention using any sealer on the switches. The "Bug Me" video doesn't say anything about it. None of the Bob Hoover articles I've combed through mention anything about it.

Can any of you give me some ideas on how to solve this problem?

Thanks for any help!

Chip San Francisco, CA

Reply to
SFbriarpatch
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Are these NEW brake light switches? They should not need any sealant nor tape! Did you use new hoses for the brake fluid reservoir? Brake lines properly tightened down and rust free? I think in CA there isn't much rust!

Clean & dry up that area well and add more fluid to see where the leak is from. I suspect the hoses, but hard to tell from Chicago! lol good luck. later, dave Reminder........ Before you criticize someone, you should walk a mile in their shoes. That way, when you criticize them, you are a mile away from them, and you have their shoes. Frieda Norris

Reply to
dave

Reply to
Braukuche

You might have air bubbles in the master cylinder. Get a pressure bleeder from

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1100 and 1101). And a AIR COOLED VW ADAPTER KIT.

14.95 Adapter 1104

From the looks of it, the fluid is leaking

Double check. Loosen each switch then tighten until it gets harder to tighten and then one-quarter turn more.

When I installed my first pair of brake light switches, I did not tighten them enough.

I dunno, but it is a possiblility. Did you install new switches with the new master cylinder? With my experience, the Brazilian made switches last a little over 3 years. I replace mine every 3 years so I do not have to get out in the cold and replace them.

I never used sealant for 15 years.

Reply to
Sleepy Joe

Extremely unlikely.

No, no sealant. These are tapered threads that require no sealant.

The leak is probably from somewhere else. Places to check:

Make sure you have the plastic elbows(s) plugged into the top of the MC all the way.

Make sure that the blue connecting hoses above the elbows are not leaking. (This is special hose, use no subs.)

Check the hard line nuts that exit the MC. Make sure they are all tight. Make sure that none of them are cross threaded.

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----------------------------------------------- Jim Adney snipped-for-privacy@vwtype3.org Madison, WI 53711 USA

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Reply to
Jim Adney

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