370z CSC Problem (2017 base 28xxx km)
 

Hey guys, 2 days ago my clutch began to feel soft like jello. The first day i started it up to go meet up with the boys, it felt normal until i got on the highway. Shifting gears clutch began to get soft, i eased up on driving it hard for the night, no pulls. As the night went on it stayed soft, but as i was coming back home, it started to get abit harder, not sure maybe because it got colder? My friends had mixed emotions, some said it will come back to normal, other's said to change fluid and see from there. I got home, parked it and checked the clutch fluid. Dirty as hell but i know that for the clutch to be soft from fluid, there needs to be air bubbles in the line's or for the fluid to be low, clean or dirty it shouldnt effect the clutch feeling if it was full. So i got back inside and did my research. Who knew that our cars were the only one's to have concentric slave cylinder problems, literally google csc and all you'll see is 350/370's. Anyways today i started it up, went on a 10 min drive, clutch was back to normal, was back to being stiffer, but then got reeeeal soft just as i got back home. As the car got warmer, clutch got softer, so i knew i was dealing with a csc problem.

After spending the last day & a half on forum's, facebook, youtube & instagram, i realized alot of guys have had this problem, but they have taken different approaches to it. They either got a heavy duty concentric slave cylinder like Zpeed or JWT, or have just deleted the csc and relocated a traditional release bearing outside of the transmission hooked up to a racing style pull-type slave cylinder.

I have just opted to go ahead with a custom fabbed delete kit made in-house at my local g/z specialty garage, and while my trans is off the car, i've decided to go with the South Bend Stage 3 6 puch Drag clutch. The Exedy NF05 lightweight flywheel, and the custom csc delete made with top of the line products, basically best of both worlds from the Z1 delete kid & the Zspeed CMAK kit.

I didn't just go stage 3 for no reason to those wondering, as i plan on going boost in the future. So this is one less headache i need to deal with for when the time comes to go forced induction.

To those who have done either a heavy duty csc or a delete kit, if you can go back in time, would you still go with what you chose & what were the inconveniences you faced, thanks a bunch.

Julian 2017 370z base 28xxx KM

I'm running a Stage 3 Southbend clutch and CMAK with a boosted performance turbo. Use of an external slave meant using custom piping from BP, which made installation of the charge piping slightly more annoying. Otherwise, performance has been as advertised. It grabs hard, it holds with 440 wtq, and it does it with minimal noise despite the lw flywheel.

My biggest question is why you're going with a custom fabricated delete kit? I don't mean this to attack your shop, but dealing with a known (working) solution seems to be a better choice than reinvention.

Dirty fluid would cause your soft pedal. It has water in it. Gravity bleed it and clean the gunk out. Most folks with success use a better quality Dot 4 brake fluid such a Motul RBF600 or Castrol (forgot the name of it).

Castrol SRF. The $70 a liter stuff. I got 2 bottles sitting on the shelf.

Get one of the solutions from Joe at ZSpeed and call it a day :tup:

Hey thanks for the reply, i totally understand your pov. I was intentionally going to go with the CMAK kit from Zspeed, but they have gotten hit hard from Covid & their means of operation were slashed in half. The average wait time would have been 2-3 months & i need this done asap.

The reason why i immediately turned away from the Z1 kit is because i read somewhere you need to fine tune the kit as your clutch wears down over time. I couldn't really find any statements on here but i would like to ask your opinion being that you seem to know, is that true? & how?

Julian

Hey thanks for the reply, i'll get onto that. How would water get into the lines though?

Julian

I have the Z1 kit installed (for about 50K miles). Adjustments aren't bad. I maybe did them every oil change and they're easy to do. However, the kit is a piece of garbage. I've had the slave cylinder fail on me 3 times and Z1 only covered the cost once (every new cylinder I got was a new design because they kept having issues). Kinda annoying since my OEM CSC never failed and the Z1 slave gave me issues :shakes head:

I picked up the ZSpeed CMAK along with a clutch kit from Joe a while ago. Haven't installed them yet but I know I won't have any issues like I did with Z1. ZSpeed is apparently on point even during Covid, so not sure where you heard there were delays...

Got it, understandable now. Like you, I had 0 interest in fine-tuning the Z1 kit on any kind of basis. JAR mentions it above. 2-3 months is a pretty long wait, so it sounds like you're probably making the right decision as long as you're working with a good fabricator. Good luck to you sir!

I guess I got lucky. I ordered my clutch kit and CMAK about a month ago and it arrived in four days.

Can you please explain where you heard this from?
ZSpeed Performance has no issues with getting parts out the same day,
We have no Covid issues.
Please do not spread false information.

Hey Joe, wow okay then my local modshop blatantly lied to me or tried to bring business to their garage, thanks for the info, i will be in touch about purchasing.

Julian

This probably should go without saying, but I'll say it anyway... if your mod shop was willing to lie about that, they will lie about other things. Pick a different shop.

:iagree:

They lied to you once. They will lie to you again. Tell them to :gtfo2:

Already on that haha, stopped bringing business to an old garage that took advantage of me when i didnt know ****...anyways quick question to you and Rusty. Should i bother changing clutch fluid & bleeding clutch line prior to getting a date at a garage which is in 1 month plus? Maybe to extend the life of my current csc (doubt that will happen) but i also dont want to make the problem worse, car still engages gears and drives as we speak. Thanks.

Julian

I'll respond for myself only, as Rusty is much more technically proficient. When I did my clutch, I had a lot of trouble bleeding the line, to the point where I had to pay someone else to do it for me (guy from Infiniti). Yes, if you can do it correctly, it'll probably extend the life of your CSC. If you can't, you won't be able to engage gears. I don't know your skill level, so weigh that for yourself.

Sounds like you've already been having issues. So a clutch flush could definitely help reduce the risk of something happening in that time. But you'll probably be fine as well since we're just talking about a few weeks. I'm guessing that most people wouldn't bother and most of the people that would bother are DIYers in their own garage.

In this case I would recommend a simple gravity bleed on the clutch. Ranger method the fluid in the reservoir and make sure it's topped off. Then open the bleed valve and let it drain. It will be slow. Let the reservoir drain until it is near the bottom (DO NOT LET IT EMPTY OR AIR WILL ENTER THE SYSTEM) and then close the bleed valve and top off the reservoir again. A single reservoir drain may not do the entire clutch system, but it will be close. Repeat the drain process again if you want to be sure.

If the seals are also going out in the master cylinder, it is my experience that pumping the clutch pedal makes the bleeding process more difficult and not easier like it should.

How much is needed for a complete fluid replacement?

I need to replace the DOT3 the car came with as my clutch pedal went soft yesterday. Running around on some farm roads at 3000-5000 RPMs with the A/C on and the ambient temp was around 85.

It came back periodically on the drive home and the reservoir was still full when I got it parked and checked it.

I figure it's about time as I topped 79K on the ride yesterday and it's the original fluid. Up until then I haven't had any problems other than occasionally a slight softness when it got hot.

Thx

I’m

Should be less then a liter. When you do it. DON'T let the reservoir go dry.