hupp

I agree with some of the others -- sounds like you have a air in the system. Avoid letting crazy creative solutions creep into your head at this point because these systems are quite simple and it's usually a simple thing causing problems.

Take a deep breath the start from step one (assuming you have the oem parts in the car).

--Remove the pedal rod at the clutch pedal.
--Bleed the clutch again.
--Remove slave from the bell with lines attached and with bleeder closed, slowly push the slave rod in until it reaches its stop. Slowly release -- then repeat this multiple times. This is done to force the last remaining air pocket in the master back to the reservoir. AND turst me, this air pocket will be there no matter how long you bleed.
--Install slave.
--Install pedal rod with correct pre-load or lack of pre-load (as mark mentioned 1mm gap) depending MY. The rod length can be adjusted by loosening the lock nut and then turnung the rod in the appropriate direction to lengthen or shorten. This is an important step and what you described previously as the clutch getting worse after 30 min sounds as if this rod adjustment is not correct. Too much pre-load causes the master piston to sit too far forward. This blocks the ports that allow the clutch/brake fluid to flow freely as the clutch is used and you essentially pump more air in with each use.

On the mechanical side of things:

Double check that you have the correct friction discs installed. You did mention that the intermediate plate was changed. Porsche upgraded the IP at some point and this IP has a longer travel. As a result, the friction discs also required replacement on some of the early cars. You probably do not have this issue on an '82, but it won't hurt to double check if you sysmptoms persist. Do you remember if one of the disc hubs was longer than the other? If so you're likely ok. Also double check the IP adjustment.

hacker-pschorr

This problem sounds familiure, how did I miss this thread?

His car is diong the exact same thing my car was doing, it was the release bearing.
The tooth snapped off allowing the bearing to flop around.

Fast forward to post #133:

https://rennlist.com/forums/showthread.php?t=273590

I was not able to see the tooth missing until I removed the release bearing from the pressure disc.


Last fall, Rick Carter's clutch wasn't as intermittent as this one, was also a mechanical issue. Long story short the ball in the upper bellhousing walked itself out:

https://rennlist.com/forums/928-forum/375454-how-i-spent-my-saturday-during-the-pca-laborday-weeknd-club-race-road-america.html

jpNcos

Good news drove 928 home today and then a nice joy ride after dinner with no problems. Thanks for all of the advice and help. I am working on a lenghtly write up on my problems so it will hopefully help others. Pushrod was to short and a 79' adjustable one that was slightly modified did the trick.

Long story short I'm sure other things will come up that I will appreciate all your help on but for now a late night drive sounds great.

tailpipe

when i bought my first 928 i also had this similar condition the clutch pedal would slowly drop over time until there was nothing i rebuilt the master and the slave cyl i got so good at bleading the thing i could do it myself in the parkinglot by myself i fiddled with it for months finally deciding the the fluid was leaking past the seals in the master cyl for some reason the seals didn't fit tight around the center shaft of the piston this was letting fluid past the seals letting the pedal drop my cure was two little "O" rings around the center shaft of the piston sealing the shaft to the seal seemed to work awsome been like that for almost 10 yrs now its prolly not the proper way to fix the problem but it seamed to fix the problem at a really cheap price hope this helps u out good luck

jpNcos

Thanks Tailpipe,

That's the outside the box thinking that I was looking for. So far it has been holdong up but have only driven maybe 30 miles so far so that is something I will watch for. Thanks again for all the help guys.

robot808

I have had some problems bleeding my clutch, as obviously many others have.
When doing Scott's method, with the slave cylinder rod to force air back to the resevoir, would you have the resevoir cap on or off? Does it make a difference?
Sorry for rudimentary question, I have only a very basic understanding of hydraulics.
Thank you.

jpNcos

I had the cap off when I did it. My 2 cents.