sinking clutch...

[louis-alain.richard@sympatico.ca]

Two or three things come to mind:

Do you still have the overcenter spring, on the top of the pedal ? This 
device should help the pedal to stay up, even with a light foot resting on 
it. It also helps to depress the pedal when the spring passes its neutral 
point. It's a PITA to replace, but cheap and worth every penny. Part number 
is 4A0 721 403. About 25$CAN here.

Now, if your pedal is sinking, and the clutch is not slipping when this 
happens, there is a problem. If you already replaced both cylinders, then 
there must be air, unless one is be bad (very unlikely IMO).

To bleed the system, I followed a procedure which involves time, patience 
and no tools. It goes like this:
1- place a lenght of tube on the SC bleeder and the other end in a jar 
containing fresh brake fluid, just to cover the end of the tube.
2-crack open the bleeder, and leave it open. Just a little is enough.
3- depress slowly the clutch pedal with your right hand, kneeling beside the 
car during this intimate moment between you two...
4- when to the floor, leave the bleeder open and let the pedal go up 
slooooooowwwwly, still with your hand on it, to let the MC pump fluid in the 
reservoir, not in the slave. If the tube end is still  in the fluid in the 
jar, then fresh fluid will enter the MC via the reservoir. The theory behind 
this is it's easier for the MC to pump fluid from a short distance above 
than from under via a long and small tube full of fluid. Simple fluid 
mechanics will confirm this...
5- check the fluid level in the reservoir, it is really easy to let it go 
down too much, then you must do it all over again.

For me, on my urQ, it worked perfectly, after trying the pressure bleeding 
and the pedal-pumping bleeding.

Hope this helps,

Louis-Alain
1983 Quattro





----- Original Message ----- 
From: "Beatty, Robert" <BeattyR at ummhc.org>
To: <quattro at audifans.com>
Sent: Thursday, October 13, 2005 3:22 PM
Subject: sinking clutch...


> Car is an 89 200q sedan
>
> The clutch has a tendancy to sink to the floor if you "ride" the pedal. 
> In
> other words, if you leave your foot on the pedal while your driving, it
> sinks lower and lower until have virtually no clutch action at all.  If 
> you
> stay off it, then it stays high and there isnt a problem, though it still
> feels a little funky.  (i think i need to adjust the pedal itself as well
> for that minor bit)
>
> The clutch is only about 30k or so miles on it and the slave and master 
> are
> both new, installed in August of this year.  I have pressure bled the 
> slave
> in both directions, from the brake master reservoir downwards and then the
> reverse of that through the slave bleeder screw.  If theres any air in
> there, I have no idea how you would get it out.  I am not losing any fluid
> so there isnt a leak anywhere.
>
> So what would cause this to happen?  I was thinking of perhaps changing 
> the
> master?  Anyone seen this problem before?
>
> Thanks!
>
> Rob
>
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