clutct

[George Selby]

At 05:07 PM 7/2/02, you wrote:
>That is when I decided to try the trick to recycle using the LF brake as
>a pump.  No help after persistent back bleeding --which some have sworn
>by.  So then I suspected the slave, but was fooled by no leaks.  How
>does that happen?  On the master I can see how a faulty middle seal can
>do it, but on the slave I'd think the path through a bad seal would lead
>to the outside world since it has no refill port like a master.
>
>I put off pulling the slave because it seemed tough:  the roll pin was
>not easy to get to or apply force to (heck, it was even hard to SEE).
>I was worried I'd have to drop the tranny.  Thanks to your BTDT, I will
>get back to that project again real soon.  Are they costly, did you
>rebuild or replace?  --Gary



I have had several cars (of several different brands) with bad slaves which
did not leak.  My personal theory (which I just came up with, BTW) is that
on the upstroke of the pedal, vacuum causes the fluid to re-enter the slave
cylinder, keeping it from escaping to the outside.  Since this usually
seems to happen when clutches are very worn, or soon after replacement, I
think it's the change in stroke that causes the problem (Many times
adjusting the rod on the clutch pedal so that the master cylinder stroke
starts farther down the bore will temporarily eliminate the non-rising pedal.)

I have tried rebuilding several slaves, but it seems they just end up
getting replaced within a month, so I don't rebuild them any more.  I'm
pretty sure the cost is around $100, I think I got mine at the local
Advance Auto (Though I seem to remember I got the last one in the country
for my Coupe, and this was several years ago.)

One area of concern, the one I replaced was in a 2wd Coupe, a Quattro 5k
might be a lot tighter around the slave cylinder area.  I removed my tranny
because I didn't see the roll pin until I had it out.  Once out, I realized
if I knew where the roll pin was, I could have done it without removing the
tranny.  So check that you can remove the roll pin, and make sure there is
enough clearance behind the slave to pull it straight back.


George Selby
83 Audi Coupe GT
gselby4x4 at earthlink.net

George Selby
70 F-100 Ranger XLT 460 C6
78 F-150 4x4 400 4 spd
85 Dodge W-150 4x4 340 TF727
83 Audi Coupe GT
86 Nissan 300ZX
85 Chrysler 5th Avenue
gselby4x4 at earthlink.net