how to bleed the hydraulic clutch on a 964/965

jeff91C2T · 09-10-2001, 10:00 AM

Just wondering if there's any advice out there on bleeding a hydraulic clutch on a 964.

The clutch when cold engages for the full throw of the pedal. As soon as the car warms up, the pedal moves about an inch before feeling resistance, then engages.

My first thought was to bleed the hydaulic pedal first and go from there. Any tips how to go about this....thanks

BRAINIAC · 09-10-2001, 12:06 PM

Jeff, here's how I do it. Get a long piece of vacuum hose that will fit snugly over the bleeder nipple. Attach the hose, then crack the bleeder loose. Put the end of the hose in a big jar. Now just go and pump the clutch pedal by hand. (since it won't return on its own) Make VERY sure that you don't let the fluid level in the brake reservoir drop more than 15mm or so below full. The pick-up for the clutch hydraulics is very high in the brake res. and will suck in air if you let it drop very low. Keep a very close eye on it. Keep pumping until clear fluid comes out, then tighten the bleeder. Now re-check clutch operation and re-bleed if you have drawn any air into the system.

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Tyson Schmidt
72 911 Cabriolet
92 C-2 Cabriolet

Britwrench · 09-10-2001, 04:40 PM

You probably need to replace the slave cylinder. Eventually, the pedal will just stay on the floor.

kr911 · 09-10-2001, 05:23 PM

I’ve been having the same problem on my C2 for over a year now. There is no real pattern to it but it usually happens when I drive uphill and then it goes back to normal by itself. I had the system bleed twice but it did not help much.
Looks like it is time for the new clutch cylinders and Wayne has both master and slave cylinders here. I wonder how difficult it is to replace them.