[sbernold]

I have an 1989 Saab 900 Turbo, 178000 miles, original clutch. The clutch pedal is perfectly firm and high when the temperature is cool or cold. But in summertime, when the temperature goes above 80F, the clutch pedal engages only when it is pushed right to the floor. If I leave the car overnight, when it is cool in the morning the clutch pedal works perfectly again. Could this be caused by an air bubble in the clutch fluid which expands at higher temperature and causes the problem? Or is this a sign that the clutch is in general failure mode?

 

[GearHead]

do you notice any leaks from any of the clutch related components?

it sounds like at the higher temps bubbles form in the clutch lines or something.Which brake fluid are you using for the clutch?

 

[peva]

Sounds like a master cylinder problem to me. Seals leaking as it gets hot. Don't think it's air in the system. Could try putting a clamp on the hose from the master cylinder when it's hot to see if you have a firm pedal. If you do, it's not the MC, if not it's down at the slave.