I went out to my 09 sedan to find the clutch pedal completely soft with no pressure at all.. I had a look at the Resivoir and it was empty! Now I've looked everywhere and can't find a leak so I've filled the resivoir back up and nothing has changed... So now I've come to suspect air in the line. I was trying to reverse bleed the system by attaching a make shift pump out of some medical supplies I have laying around and attached it to the bleeder screw pressed the clutch in and tried to push the fluid back through to force the air out... Didn't work .. For some reason I can't force the fluid back through the system... Am I missing something?
I'll post a picture of the set up I was referring to.

 

I don't think that thing you've put together there will do it. Maybe gravity bleed it followed by the old fashioned way of using the pedal to pump the air out. Slowly and methodically. This clutch system I can be a bit tough to get all the air out.

 

If your reservoir was empty thats because of a failure of some sort. Most likely the CSC has failed.

 

Yep. And doesn't the fluid typically drain into the inside of the transmission?

Thats why no external leaks are found.

 

So for an update I could never get the thing to reverse bleed. I saw a post in the 350z forums about a guy using a pump oil can and attaching it to the bleed valve and then engaging the clutch then forcing fluid (and the air) up through the system. However I couldn't get it to flow. I tried to do the two man thing and pumping slowly.. There is brand new brake fluid coming out of the bleeder valve, but when it's closed and the pedal is released there is no pressure. It feels like I'm chasing my tail. When I pump the clutch I hear fluid moving through the line pushing air around. The best way I could describe it is if you held a gel bag in your hand and squished it. I guess I'm gonna be replacing the csc, but it just seems a bit young of a car to have this happen already.

 

Previously clutch fluid didn't just magically disappear. It had to have leaked out someplace. More than likely your slave cylinder has failed. If that's the case you will not be able to bleed the system until it's replaced.

Search for various other threads on here relating to the matter. In a nut shell, to replace the slave the trans has to be dropped. Good time to replace the clutch itself as the added labor is minimal. You should also replace the master cylinder at the same time.

 

If this work is done under warranty (replacement of the CSC), Do dealerships allow you to purchase an aftermarket (upgraded) CSC to be installed?

Or do they only allow certified stock Nissan parts?

 

You'd have to discuss this with the dealer. Some do, some don't. Majority will only replace with stock. Convince the dealer you realize there would no longer be any warranty on this part and are ok with this.

I have an extended 8 year warranty on my car, if the csc fails early on, they can install a stock part. If it fails closer to the end of the 8 years then I'll definitely be pushing for an aftermarket/HD component.

 

Mine blew out at only 18K miles. There have been a number of people here on the forum with a similar story. It was still under warranty at the time, and lucky that it was because it's a $1400 repair at my dealership. That's mostly labor costs, because you have to drop the transmission to access the CSC. In hindsight, I should have had them install the Z1 CSC, but I was very pressured at the time with other considerations, so they used OEM parts.

Coincidentally, I was just communicating with Ryan at RJM Performance about his claims that the RJM clutch pedal reduces/eliminates the root cause of this design flaw. However, that's kind of a Catch-22 because replacing the pedal assembly would also likely void clutch warranty problems. In any event, it's a must-have modification, IMO.

Here are some links for you to read up on it:

https://www.myg37.com/forums/g37-sed...-assembly.html

http://www.rjmperformance.com/370z--...ssemblies.html

Nissan 370Z Forum - View Single Post - RJM Clutch Pedal System for 370Z - Fully Customizable Clutch Feel & Stroke

 

So we took apart part of the housing before deciding to pull the entire transmission. We didn't see any fluid in there, so ordered a master cylinder and ss clutch line... Hypothetically, if the problem is solved what is the likelyhood the csc is soon to fail? I've always heard that when the csc goes the master follows, so I was wondering if it were the same in reverse.
Just trying to get out of this a much cheaper way. If it does wind up being the csc then I will have replaced what needed to be replaced anyways... And will most likely get the z1 clutch with the csc delete kit.. Seems to be the best way to ensure it won't happen again, and if it does it will be much easier to fix

 

If you drop the transmission and don't replace the CSC, I promise that you'll regret it. The part isn't that expensive as I remember, 100-200 or so? Replacing it while the transmission is already out will save you the 5-6 hours labor of doing the exact same thing again a few months down the road. Actually anytime the time the transmission is removed if recommend to replace it preemptively (unless you just already did so) because it's a part that's prone to wear out.

 

Yup, all symptoms point to the csc. Mine blew out at 78k, out of warranty. No pedal pressure, no visible leaks. If you dropped the trans you definitely should have replaced the csc like BB said. Even if hypothetically the csc is good (I'm guessing less than 5% that it's good) it's prone to failure and you already are having clutch problems.I replaced both the master and slave, parts aren't too bad and obviously you can do the labor.
I did have an issue bleeding the system since both my master and slave were new and therefore bone dry. Pressing the clutch pedal with the new parts installed, I couldn't bleed the system. Here's the fix. Instead of pressing the clutch pedal to try to bleed it, disconnect the clutch pedal from the master cylinder piston and manually push the master piston a few times. The difference in distance that the piston travels manually vs via the clutch pedal, causes the master cylinder to catch the fluid and you can begin bleeding. However if this still doesn't work, and you haven't replaced your csc, well then get ready to drop the trans again if you reinstalled it. Good luck, it's a bit of a pain in the *** but nowhere near impossible. Took me and friend about 4 hours for the csc and then me alone another 2 for the master with the bleeding issues. Hope it all works out

 

So here's an update, I purchased the southbend stage 2 and fidanza flywheel to pair with the HD CSC from zspeed. Several people on here were saying it was a good idea to do it while the transmission was down anyway. So joe at zspeed hooked me up with a modified kit for a great price +shipping .. Although the package arrived with no csc in it ... Joe overnighted it to me so no biggie.
Anyways on to the point
I absolutely love the new clutch. It is perfect for dd. nice firm grab and not to stiff. ALSO .. Big bonus here, the quiet disk option with southbend WORKS . I have absolutely no chatter whatsoever.
There are a few minor issues I would like to discuss though.. And I hope they are minor
1. My speedometer, odometer, abs, Vls do not work and all the lights are lit up on the dash (slip, brake, vls off, abs). I asked another friend with a g to see if he had ever had this problem and I looked around on Google and here. Buddy didn't know, but Google had some horrifying "no specific answers" that would lead me all over the place. Now what I'm hoping is, is that there is a vss sensor or something that is around or inside the tranny that the guys forgot to hook back up... Because a code reader stops and says vss problem and you can't clear it. Anyone know if I'm beating on the right door here?
2. The pedal feel is "iffy" what I mean is that the engagement part is significantly less and smooth, but sometimes it's really soft up to the engagement point and other times it's consistently stiff... I found that if I pump the clutch prior to engaging it sometimes it's consistent. Does that make sense? My question is could there be air in the line making the pedal feel not consistant?

 

I would try bleeding it again. The best method I found is to gravity bleed the system to ensure that no air enters the system.

BTW, when the shop dropped the tranny did they see the fluid that spilled out? Was the CSC confirmed to be the culprit?

 

Yes 100% was the problem.. Stress cracks on the inner ring where the factory pressed the metal... It was cheap material on the inner ring that when pressed caused stress fractures... No wonder they randomly go out .. Kinda a roll of the dice in respect to which one of them has the most stress cracks or place of the stress cracks. Mine could of had less than the persons who went out at 18k miles.
Basically... It's not a matter of "if" but "when" will it go out.