Clutch pedal goes slack and falls to the floor

[masokotanga]

So I was driving my 91 300zx NA when the clutch just went to the floor, basically on its own, just kind of pulled itself to the floor and stayed there, pulled it out, it was totally slack. Towed the car, it sat there for 2 days, then pulled the clutch pedal out again, and all the sudden there's pressure again, the clutch works fine. Take it to a shop, they said they can't find anything wrong with it. I proceed to drive it again for the next week, no problem, til it happens again. This time I pull the pedal out and there's immediately pressure again, clutch seems to work again.

Anyone have any ideas about what this is. Slave cylinder?

[Chattzx]

Yeah your slave/master clutch cylinder is going out. Replace it soon.

[robomatic12]

Either one of the master or slave could be leaking, look for clutch fluid along the firewall. Check clutch fluid level in the master cylinder.

I would replace both of them at the same time.

[marty1mc]

I would also replace both units. If one is bad and the fluid is dark, then rubber is breaking down. But, as RM12 said, look for fluid at the firewall (inside) where the master enters. If it's wet, then the master is leaking. Also, you can peel back the rubber boot from the slave cylinder and see if there is any fluid there as well. That would indicate the slave is failing.