odd hiss, clutch master issues

[Huw Powell]

The story so far... patient is an 87.5 "special ed" coupe.  Needed
tranny replacement due to PO's error in clutch slave removal.

Did that the other night with Nate, installing a new release bearing and
clutch slave at the same time.  Didn't really bleed it right away, so of
course the clutch did not work yet.

A few days later, bled it fairly well with my horrible homemade pressure
bleeder, and got "some" pedal - if jabbed fast and released, the
pressure would overcome the over-center spring and return the pedal.  If
held down for any length of time or pressed slowly, it would stay down.
  SO I figured it couldn't hurt much to throw in a spare old master
cylinder from parts car I have.

After installing that one and bleeding it the same way, the pedal would
consistently return, so I took a short test drive.  The clutch would
only disengage at the very bottom of pedal travel, but worked for a bit.
  managed to upshift a few times, turn into a driveway and stop, back
up, back into 1st and 200 yards back home - but at the end of the test,
the pedal no longer released the clutch.

Now when I press the pedal, once I get past the over center half way
point, the pedal drops almost on its own, and I hear an odd "hiss" from
the general area of the master.  Anyone btheardt?  I don't mind throwing
in a new master if this just means I trashed an almost dead master.  I
promise I will even reinforce the firewall a bit!

Just curious if anyone has more than a theory, has actually heard this
before.  It's too messy under the hood to see any leaks of any kind,
though I will do some more observing with another set of feet on the
pedal, soon.

Thanks!

--
Huw Powell

http://www.humanspeakers.com/audi

http://www.humanthoughts.org/