Upgraded Clutch Slave Cylinder Fails Again!

Originally Posted by pbs370z

Back in July my clutch (CSC) orig. Nissan slave cylinder failed so I upgraded to the new and improved HD CSC (with new MC and stainless steel line upgrade) from Zspeed (ZSpeed Performance Replacment HD Clutch CSC Heavy Duty Slave Cylinder Kit) (along with a new Clutch & Flywheel) which has been touted here on this forum and on the Zspeed website to fix the infamous CSC failure problem in the 370Z.

Guess what? After 10hrs and about 500 miles of driving the upgraded CSC failed. That's right - pedal to the floor again! This happened after 2 sessions at the track (open lapping days) of about 30 minutes total (15 min. max sessions) each day, and then the last track day of 4 laps (10 minutes) which was a nice cool 75 deg. day. I came in to the pits after 4 laps, sat about 5 minutes and then went back out for 1 more lap when the CSC failed. I'm thinking heat caused the seals to fail.

Update (9/18/2015): CSC did not fail.

Right now I'm wondering if this new CSC (Zspeed Item #: zsp2006) is really any better than the stock Nissan unit.

Is this really a proven fix, or am I just really unlucky?

At $800 (labor) a pop for trans. R&R and MC/CSC replacement plus $325 for parts, I don't think I'll be putting another one of these CSCs in my vehicle.

Any comments on this Zspeed CSC setup are welcome.

Also: To be fair, the CSC has not been removed yet to confirm its bad, but I believe it is since the MC makes good pressure. I'll report back here to confirm my suspicions.