Sticky: (Official) 370Z Clutch Pressure (CSC) Failures

MJB

IDK, I just think you guys over think/analyze when it comes to fluids for this car. There is nothing special DOT 4 or 5 has over DOT 3 other than they have a higher boil point. Unless you are on the track, you are not going to boil your clutch fluid with street driving. The problem with the stock slave cylinders lies within the seal itself. Its a crap design and it fails, regardless of what fluid you put in there. I read thread after thread of people spending hundreds of dollars on high end oils, expensive brake fluids, ect, when in reality its a waste unless you are building a flat out race car. DOT 3 is perfectly fine for our clutch hydraulics system. When dealership mechanics starting put in this so called "GT-R" fluid (which is just DOT 4, nothing special about it) people now think its a cure-all for these CSC/CMC issues, SMH.

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09 Nismo #0483 sold. Viper or C7 next time around.

radensb

Have to disagree with you here. My fluid did fail within 6 months of normal driving and zero track time. And according to my service record, it was GT-R fluid. When I flushed it out, it was black.

MJB

The clutch line has a thermal fiberglass wrap on it, so unless that was removed and the line was actually touching the cat, how is it going to boil under normal street driving? And about your fluid being black, that's because the seal on your Csc was going bad and allowing dirt and debri into the system. If you feel the Dot 5 is a fix, then have at it... But I guarantee you that your stock Csc will fail again.

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09 Nismo #0483 sold. Viper or C7 next time around.

radensb

The fiberglass insulation is a joke. It only insulates the rubber hose that jumps to the CSC. The metal tube that runs up to the MCS is completely un-shielded. Im sure that the stock CSC will go out again, but seals failing after 6 months? I dunno about that. I had no leaks and I am not rough on it. It has to be heat related. How else can you explain regaining a normal feeling clutch after turning the car off for 10 seconds? Then it deteriorating to the point of 'un-shiftable' after another 60 seconds of driving?

I will ask about this when my CSC goes out again. I'm have a 5 year extended warranty that covers this type of failure. I thinking that they will not want to put anything other than stock in or it would void that warranty, blah blah blah... Nevermind that its higher quality and will prevent them having to fix it again in the future.... Warranty Logic.

MJB

The 300zx has the same clutch layout with the line right next to the cat, same with the 350z DE (external slave but clutch line in the same spot)... I don't hear about their CSC going out in record numbers like on here. In fact, the 350z HR and 370 have basically the same csc and both have extremely high failure rates. Like I said before, I believe its the seal within the csc itself. So if its heat related, why aren't guys boiling their clutch fluid when they have a Zspeed HD csc installed? The clutch line is in the same spot, no difference except the csc isn't made out of cheap plastic and uses better seals. But you seem pretty convinced its your fluid that is boiling during normal street driving so have at it. At least you have an extended warranty so when it goes out again Nissan will have to replace it. I had the HD csc installed over 2 years ago and haven't had an issue... Come to think of it, out of the hundreds that have installed the HD csc, I think I've heard of 2 failures.

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09 Nismo #0483 sold. Viper or C7 next time around.