You might want to look at this recent post:
https://my350z.com/forum/maintenance...es-so-far.html

 

That would explain why I had the clutch pedal stick half way up and why I have
a lot of end play. If the Hydraulic fluid is not forced out of the CSC it would not
create back pressure in the master cylinder and assist with return. GOsh I just
repeated what you said... DUH I need sleep Thanks for that I will relay that info
to the Nissan rep I have been talking with.

 

im not sure if u guys messed with CSC or dealer when changing the clutch but CSC should not be reused if it's removed it says in service manual which will cause internal seal leak.

my trans was replaced on 25k mark and then CSC went kaput not long after so it took some research to find why. now the clutch is starting to slip if i drop clutch pedal too quick it would just get stuck half way and engine revs but car barely moving then smells like burned clutch but so far it's been hanging like this for good 10k miles...

 

Yeah Makizm69,

Sounds like the issue I am having it really sucks *****. Do something about it
before your clutch is toast and messes up your flywheel. Mine started slipping
one day and then just got worse less than a week and it took me ~5min to
get up the 40mph. What I'm saying is don't get stranded.