88 80Q brake fluid reservoir cap

[Ryan Hoitink]

Brake fluid is hygroscopic, and it would be a terrible idea to have the
reservoir open to the air any longer than necessary for bleeding/etc.  The
more moisture absorbed from the air, the lower the boiling point of the
fluid in the lines, and the more dangerous things get.  Ever notice how
there are rubber accordian-style boots on some master cyl. caps?  They're
there to allow expansion, while not exposing the fluid to the air.  Besides,
personally, I wouldn't feel too good about driving around with any part of
the brake system out of spec., no matter how small.

-Ryan

-----Original Message-----
From: quattro-admin at audifans.com [mailto:quattro-admin at audifans.com]On
Behalf Of Livolsi, Stephane
Sent: Wednesday, September 20, 2000 5:48 PM
To: 'Audi Quattro List'
Subject: RE: 88 80Q brake fluid reservoir cap


Dirt isn't the only problem, though.  If I recall correctly, brake fluid
is hydroscopic (sp?) or is it hygroscopic?  Anyway, it means that it
readily absorbs moisture from the air.  I don't think it is a good idea
to have a brake fluid reservoir open to the atmosphere. But, I could be
wrong - anybody else know for sure?
Stephane Livolsi
Williams Lake, BC, Canada
86 5KTQ (If you don't know what it means, you aren't in the club)


>>I opened my hood to check oil for 1st time since my car returned from
having
>>AC compressor etc redone AGAIN a few weeks ago & noticed that cap to brake
>>fluid reservoir was cracked -- in a circle, as if it had been cranked down
>>too hard -- dealer/service place says that they don't have part & can't
find
>>it in their catalogs -- of course they claim no responsibility & I know
that
>>would be too much to expect, tho I've never open or shut the reservoir &
>>they are the only place to have worked on it (5 times?) in last 6 months &
>>they changed brake fluid 2 or 3 visits/months ago
>>
>>Any ideas where to get the part?
>>
>>Is it really not available?
>>
>>How bad is it to run car with the crack?  levels look OK
>>
>>Thanks again
>>
>>Cory B
>>88 80 Q
>>Houston TX