Brake servo/master cylinder

[catlotion]

an issue that's come up on the forum before, but just wanted someone to make me feel better about my rapidly emptying wallet...

I've just bought a new master cylinder as there was fluid loss in the front part of the reservoir. I did find a small leak in the rear wheel cylinder so replaced both of those but also found that the paint had been stripped on the front of the servo where it meets the master cylinder so thought it was best to replace...

I removed the servo last night and there was quite a lot of fluid in there - but didn't really look like brake fluid as it was red...?! looked like transmission fluid to be honest (obviously impossible). I did thinkthat it might be petrol from the vacuum hose but it doesn't really smell... Anyone have anyideas? I'm going to try and dry it out so hopefully won't need new seals/diaphragm. Do you think I can wash it out with anything? :?

The old cylinder looks ok so hoping I haven't wasted money on the new one - maybe the stripped paint was just because of careless filling in the past?

cheers!

Toby

[jbuckl]

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The transmission, if its a borg warner auto, has a breather pipe which canoften vent fluid in this area.

The likelyhood of the atf getting inside the servo is slim though.

Last timeI changed a servo, the fluid inside was brake fluid, but red.....maybe it leaches the colour out of the servo internals?

[catlotion]

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my bw35 certainly has been known to 'vent' fluid in this area but not sure that much could get in the servo...

any thoughts on how I clean the servo internals? Do you think flushing it out with something is a bad idea? It's damp in there from the mystery fluid anyway...

[GDPR]

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jbuckl wrote:

The transmission, if its a borg warner auto, has a breather pipe which canoften vent fluid in this area.

The likelyhood of the atf getting inside the servo is slim though.

Last timeI changed a servo, the fluid inside was brake fluid, but red.....maybe it leaches the colour out of the servo internals?

They used to assemble the cylinders and servos with the Girling Red Brake grease - maybe that was what you found mixed with leaked fluid?

[catlotion]

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ah-ha! that sounds like it could be it. It was quite thin though so I reckon I've done the right thing getting a new master cylinder as it was nicely diluted (with brake fluid I presume).

New master cylinder shouldn't be affected by mucky internals of servo should it? It's only a mechanical connection isn't it...

[GDPR]

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I suppose the worst that could happen is the fluid causes the servo diaphragm to deteriorate a bit quicker..... if it failed at least the brakes would still work

[catlotion]

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cheers.

do you think a wash out with warm water and thorough drying would be a good idea?

got my other parts today so may be back on the road by next week if all goes to plan... :dude:

[GDPR]

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Unless it was really bad I don't think it would make a lot of difference now...... however providing it is dried out straight away washing with just water wouldn't harm and it would only flush away the fluid and not the grease