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

Shutterjock

The same thing happened to my 2010 370z last spring and it's having the same issues currently -- so I'm up on what the problem is. Mine started on this long trip once I had the opportunity to open it up and slip into fifth and sixth gears. The clutch pedal began going limp and I had to reset manually, i.e. lifting it up with my foot. Not a good feeling.

I guess my question is why hasn't there been a "complete fix" to the issue. I'm surely among enough with this same issue that a final fix should have been sent to dealers.

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Shutterjock
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Jsolo

Given how few MT's are sold, probably cheaper to just fix them as they come in rather than issue a proper fix. Some mba crunched the numbers no doubt.

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G37S Sedan 6MT, Eibach swaybars, Invidia Exhaust, Weaker Clutch Pedal Spring

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Zensation

Wellmy csc failed on the highway about 20miles from home. i got to the top of the exit ramp of my exit before it stalled. managed to get it started in 2nd gear by using ignition and then flooring the pedal to keep it going. got to a parking lot 2 miles from my house and called AAA. I took off the transmission today and im going to upgrade to the zspeed HD CSC and use this time as well to upgrade the clutch and flywheel with a competition stage 1 clutch and 17 lb flywheel.

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370z NISMO 0675 327 rwhp 280 rwtq - sold.
FD RX7 single turbo 508hp - sold.
Lexus IS-F 5.0L V8

Fountainhead

So Zensation,

Your CSC failed by losing pressure to move the clutch spring in, correct? So that would mean you were losing fluid pressure right? So then you would have clutch fluid leaking from the CSC (every pedal press), otherwise the closed system would work, unless the master wasn't pressurizing the fluid to move the CSC diaphragm/bellows out right?
That's my understanding of the hydraulic clutch operation, it's a closed system and the primary failure mode is an open in the system.
If however, the clutch must be "pumped" up to work then that would suggest failure of the master cylinder.

I realize I'm beating a dead horse but I'm trying to rationalize the reported CSC failures that apparently have no fluid leaks associated with the failure (I know I'm assuming a lot here). I just don't understand how the CSC fail mode can be anything other than a leak, but guys report no fluid loss when their CSC is totally inoperative, can't put the two together.

So please let me know what the failure mode ends up being, a leak? If so did you lose fluid, etc.?

Jsolo

Clutch failures with no visible fluid leaks usually involve failure of the master cylinder. Rather than pressuring the fluid in the MC/hydraulic line, the MC piston is simply moving back and forth with fluid leaking past the seals in the MC bore. You can call this an internal leak. Level in the reservoir would not change.

So technically it's not a CSC failure and a hell of alot cheaper to replace. However the symptoms are the same --- no clutch pedal [pressure].

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G37S Sedan 6MT, Eibach swaybars, Invidia Exhaust, Weaker Clutch Pedal Spring

For sale links

Fountainhead

Right, my point is that guys report CSC failure but with no fluid loss, take to the dealer, dealer "changes CSC", and sometimes CSC and MC, then clutch works, but I'm wondering if they only change the MC and that's the issue and charge for CSC work? Either way it's a PIA.

Jsolo

^^Good point. I know some dealers can be shady, but if it's warranty, there's little a customer can do.

If non warranty, I'd be demanding to see all the old parts before I pay a cent. I suppose same can be requested for warranty repairs too. For the latter, I doubt nissan would approve a CSC labor line without an associated parts line. Not sure if they require return of the original part or not, but that would keep dealers from defrauding the warranty claims depts.

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G37S Sedan 6MT, Eibach swaybars, Invidia Exhaust, Weaker Clutch Pedal Spring

For sale links

Zensation

Yeah so i pulled my transmission and the inside of the bell housing was soaked with brake fluid so it must have failed in a big way. I noticed no issues prior to the one time i just touched the clutch and it just fell to the floor. The master is fine though cuz it pressurizes fine when i pulled the line off the bell housing.

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370z NISMO 0675 327 rwhp 280 rwtq - sold.
FD RX7 single turbo 508hp - sold.
Lexus IS-F 5.0L V8

Zensation

What is probably happening here is that somehow their line may have gotten air in it or maybe over heats bad quality fluid. They may change the master and the slave but then the next thing they will do is bleed the system with new fluid. My guess is all they really needed was to bleed the system in the first place cu if either cylinder fails there with be wet spots somewhere and a notice of fluid loss.

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370z NISMO 0675 327 rwhp 280 rwtq - sold.
FD RX7 single turbo 508hp - sold.
Lexus IS-F 5.0L V8

Fountainhead

Ah, definitive proof. I plan on changing mine myself also when/if it fails. Problem is no one knows when! I am debating just going and buying MC and CSC and fluid and storing them in my garage just-in-case.

May I ask how you got your car up in the air? Lift or Jack Stands or what? Your method? I know it's been discussed several times before but everyone has valid input as to how they solved the problem i.e., lifting the car, methods, etc.

Thanks!

Jsolo

My suggestion, if you're going to start this whole mess, do the MC too. One less thing to bleed and deal with in the future - especially if your car is higher years/mileage and/or is driven aggressively. My 2¢ worth.

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G37S Sedan 6MT, Eibach swaybars, Invidia Exhaust, Weaker Clutch Pedal Spring

For sale links

DIGItonium

If you're reusing the clutch assembly, make sure the surfaces are cleaned real well to prevent other engagement issues.

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Zensation

Yes I put the car on jack stands I am going to write a comprehensive diy when i finish the project (when the new competition clutch and flywheel come in with the hd csc) but basically where im at now:

1. jack the car up front and rear on jack stands.
2. I have the hks exhaust and the resonators on the mid pipe have a cross member welding them together. I had to remove those mid pipes but not the h pipe or the muffler section so that was nice.
3. undo the 4 bolts connecting the drive shaft to the rear diff. it just pulls out of the transmission.
4. Remove shifter assembly from inside the car. (i did this as step one before i jacked up the car). Use one of the many diy's to do this. its pretty easy.
5. remove all the mounts for the main wiring harness at various points along the transmission. remove all the plugs from their sockets as well.
6. at this point the transmission is in a somewhat free state. the next step is to remove the bottom plate under the engine to gain access to the back of the bell housing as the bottom tranny bolts thread in from the engine side.
7. remove all bell housing bolts. they are all pretty easy to get to excpt the top 2. I couldnt even see the top 2 i however managed to use a frankentool as follows(17 mm socket a 6 inch extension then a universal joint connected to a 18" extension into the socke wrench) you can reach up and feel the 2 bolts at the top of the bell housing so just fish the tool up and onto the bolt. this sounds way more complex than it was the bolts arent torqued down super tight as their purpose is mainly to keep the tranny from walking along the spline.
8. Once this is done get some sort of jack positioned somewhere on the tranny and apply a slight bit of pressure up not too much remember it aint going anywhere. Undo the 2 bolts at the back of the tranny holding th cross member black tranny mount to the car.
9. slide the tranny back and out. Have 2 people cuz that B*&%# is heavy!
10 the csc is right there in front of your eyes inside the tanny bell housing behind the throw out bearing. remove set on fire and mold the plastic into something that shouldnt be allowed anywhere near the functional part of a hydraulic system. If you got that far i think youll be good....

this is my first time doing anything this 'serious' with a car and im finding it rather easy. If I can do it so can you. Just took me like 4 hours to get it out of the car.*****also do yourself a favor and drain the tranny fluid and dont smell up your garage like i did. its free to come out the drive shaft opening at the back. GL

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370z NISMO 0675 327 rwhp 280 rwtq - sold.
FD RX7 single turbo 508hp - sold.
Lexus IS-F 5.0L V8

Techracer

On my way home yesterday I was starting out from a light and was surprised when my car lunged forward like I didn't know how to work a clutch. Then I noticed the pedal had not returned to the normal position and the clutch was engaging right off the floor. within a mile I had to clutch pedal at all. I nursed her home using manual rev matching to shift and luckily it was all freeway except the last few miles and only one light that I was able to coast through a right turn.
Today the dealer said the repair was to replace the fluid with Dot 4 GTR and this seemed to have fixed the issue. I asked him what his gut feeling was and he said he expected he would see me back at some point.
The car is a 2013 Nismo 370z with 2100 miles on it, only had it for three months and while I have done a few fast launches I am generally very easy on the car. Haven't had trouble with a clutch for 30 years, so this is disturbing.

L33T Z34

PLAS-TEKE CSC...it craX...NeeSan cost-cutt'N....U say u'r clutch hi-dralic fluid is contaminated? Replace w/metal Z speed CSC and DOT 4 hi-dralic fluid...Fixt!