Originally Posted by 6SPD_FTW

This loss of clutch pressure is a recurring thing that occurs on 05+ V6 Altima's, MT Maxima's, the 350's and 370's. My previous 2007 Altima 3.5SE did this crap 2 times in 40,000 miles and that's it.

It's a pretty routine thing, from the research that I've done, that the clutch pedal will sink to the ground, loose pressure and will remain that way for varying amounts of time. It seems like regardless of which vehicle it is, the pedal will return to normal given enough time. Some just have to sit for a while longer than others. The Altima's and Maxima's were narrowed down to something in the master cylinder (most likely). Even on older vehicles that had a traditional slave cylinder/TO bearing setup, this failure still happened on them.

If the CSC fails, it would stand to reason that the clutch pedal would still return to normal position when released. There's a big spring on the clutch pedal that pulls it back up. Of course Nissan uses some funky fulcrum/pivot point in their clutch pedals which I think has a big part to do with this.

Late,
Trav