Hissing Sound until brakes are applied - 1987 Audi 5000 Quattro

[Fred Munro]

Don't take this to the bank, Dave, as it's been a long time since I was
digging around in an '87s pedal cluster, but I think there are some vacuum
switches in there to de-activate the cruise control when you depress the
clutch or brake pedal. Could be wrong on this one - check the Bentley.

Fred Munro
'94 S4

----- Original Message -----
From: "Dave Marshall" <autolit at bmts.com>
To: <quattro at audifans.com>
Sent: Thursday, June 07, 2001 6:16 PM
Subject: Hissing Sound until brakes are applied - 1987 Audi 5000 Quattro


> Hi All
>
> New problem today.
>
> With the engine running, there is a hissing type of sound coming from near
> the top of the brake pedal.  Step on the brake pedal and the sound goes
> away.
>
> I have the Bentley for my car, but I can't seem to find where there may be
a
> vacuum hose or what ever that is leaking.
>
> I have dug around in there, but can't find where the leak is as of yet.
It
> is definitely right close to the brake pedal.
>
> Any ideas?
>
> Thanks
>