'91 964 gear stick

sdycus10 · 10-06-2003, 08:01 PM

I bought my car about a year ago with 40k miles on it. Over the summer I noticed a problem starting to occur with first and second gear. When the engine is hot for a while and the temp outside is above about 80 the clutch doesn't disengage the engine. This always happens when I am downshifting and coming to a stop. Otherwise the gears and clutch work just fine. I have a good mechanic and he, of course, cannot recreate the problem. I think because it has gotten colder out. If it were the DMF or clutch bearing wouldn't I have difficulty getting it into gear also? Any ideas what to check? Thanks for any hints.

FRED/LI · 10-07-2003, 03:40 AM

Bleed the clutch slave cylinder on the top of the tranny/clutch housing. That may do it.
More likely, replacing the cylinder is necessary.
These seem to lose a little capacity when hot from exposure to the engine heat.
One remote possibility which could be easily checked with the floorboard off is the roll pin holding the clutch pedal. Hold on to the plunger arm and move the clutch pedal by hand. If there's slack in the movement, the roll pin may be failing. Been there twice.........

C.P. · 10-07-2003, 07:16 AM

Hi,
I had exactly the same symtoms and it was caused by worn engine and transmission mounts. Try jack up the car underneath the engine, if there is excessive movement of the engine then the mounts are worn.

sdycus10 · 10-10-2003, 04:40 PM

Thanks for advice Fred. My mechanic tried power flushing the entire hydraulic system both brake and clutch. The fluid that came out was pretty bad looking. I haven't had any problems since and it was hot today. My theory is that moisture got into the brake fluid and when it got hot it could no longer disengage the clutch. It could have been air but the fluid was pretty bad. I checked the mounts and they don't appear to be worn.