Upgraded Clutch Slave Cylinder Fails Again!
 

Update: 9/18/2015 CSC DID NOT FAIL. Was the clutch itself. (Made deletions of wrong statements I made originally)

See my reply post below in this thread: "Clutch Fails Again: NOT a CSC Failure" (Post #30).

Clutch disc was not broken in enough which caused the clutch to fry. My fault - not the clutch or CSC.


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.


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. (This has been proven wrong - nothing wrong with the new CSC unit)

Did you wrap insulation around the hydraulic line down by the exhaust pipe?

They (Mac Autosports) did. Line is wrapped w/heat shield with the upgraded line. And: Motul (Dot 5.1) fluid.

What kind of fluid did you use is the big question. Dot 3 brake fluid is not going to cut it. Bleed it again with Motul 600,
It appears you overheated the fluid and caused it to boil.

Seconded. It's much more likely you boiled the fluid, especially after 30 minute track sessions. You should flush your clutch (and brakes) with Motul RBF 600, or if you're like me and never want to deal with a dead clutch pedal again, Castrol SRF.

Wasn't there some issue with the HD CSC and some brand of aftermarket clutch? Anyway boiling would temporally make the clutch stick, after it cooled down it should work normal again. And if he hasn't replaced the stock cats then the heat shield on them should prevent any overheating of clutch fluid.

Correction: The kit came with the Motul (Dot 5.1) which was used in the install.

30 min total. 10 minute track sessions.

Eng. is stock with stock Cats.

Ya, I am scratchin' my head on this one.

Motul RBF 600 or Motul DOT 5.1? They're different products, you want RBF 600.

I've boiled my clutch fluid on the track with stock cats dozens of times. The catalyst temperature reading from my data logger frequently reads over 1100 degrees! It's essential to have a fluid with a high wet boiling point, like Motul RBF 600 or Castrol SRF.

Doesn't sound like much, but then again, I've boiled my clutch fluid after one lap (2 minutes). When the pedal drops to the floor, you can lift it up with your toe and pump repeatedly to get it back. However, once this has happened, you need to flush the fluid. Motul RBF600 should last 2-3 track days, while reports are Castrol SRF might last half a season or more (I'll be trying it out at Willow Springs in two weeks).

I'm curious to see what the autopsy shows.

If the seals failed, you should be able to see fluid where it doesn't belong and reservoir level should drop. If it's not the seal and the MC is good (have you tested it at operating temp?) then you're probably boiling the fluid. Or maybe you just got a bad CSC - it happens even with the best manufacturers. Can't rule out a bad install, yet.

Oops! My bad. Its the Motul Dot 5.1.


Everyone: thanks for all your thoughts on this!

This happened to me yesterday at 46,000 miles. Thinking about the Z1 Clutch Concentric Slave Cylinder Elimination Kit from Z1motorsports. Any suggestion?