The oem masters fail just as often as the slaves, and if you change the slave without changing the master you can expect quick failure. Many people here are on their third or fourth master. The HD one costs more but won't fail.

Some people have had lots of problems with the master. RJM has an HD CMC available now. Even if you don't upgrade, you are still going to want to replace or rebuild your OEM master whenever you replace the CSC.

Just spoke with Joe at ZSpeed and he is assuring me the CSC is not failing and that it is the CMC. He saying that just because it was acting up two days ago but yesterday and today is functioning fine. So looks like for now I am going to just replace the CMC and then in the very near future replace the OEM line as well as CSC.

OK, then I'd recommend that you consider the RJM HD CMC rather than OEM version. The install is virtually the same.Simply go to the RJM Performance website and you can review the specs and download the install instructions. While you're at it, you may want to take a look at the RJM clutch pedal assembly. A lot of us have switched to it because of the "finicky" nature of the stock pedal assembly. It makes shifting a whole lot easier and more pleasant. A quick search will reveal a number of posts on this site that speak highly of it.

Baby steps first. I'm on my third Z and the only time this happened to me was on the track. When the fluid gets hot or old this will occur. Even my 2015 Nismo did it when she got hot after a dozen track events. Bleed the fluid out from the bottom bleeder and replace it with some Motul 600. Sounds like it only happened once so I'd start there and make sure wifey isn't slipping the clutch or riding with her foot on the pedal.


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I really don't know what people consider a lot of failures, last I checked about a year ago, there were fewer then 5 people who actually posted on here that knew there MC had failed. All the other replacements have been because they don't know what failed, so replace they replaced both. Which isn't a bad thing because the MC is pretty cheap and easy to replace, but it's a far cry from saying the MCs are failing as much as the CSCs.

CSC Failure = No fluid in the reservoir, even if you refill it and clutch doesn't work or works poorly.

MC Failure = Reservoir full but Clutch doesn't work even after you have bleed the system of air.

And if you've been going through MCs ever few miles as one person had it's probably not the MC but something else causing the MC to fail constantly. If my battery is failing every few miles the solution isn't to get a better battery but find out what's killing the battery.

Totally with you there.

And also worth mentioning after the phone call from Joe with Zspeed. He said he actually replaces them quite often. I think you don't see threads about the CMC failure because of exactly like you said, someone may think its a CSC and misdiagnose it and then replace the entire system.

And another point according to Joe, the CMC has been revised from Nissan. So the older 370's, like mine being a 2010, has the older version that is prone to failing, but the new version, which they sell on their site, should be more than sufficient for a totally stock car.

Well I got a Z1 Elimination kit and a 5+ year 35k+ old MC, I'll post when/if it fails.

My 09 still has the original OEM master in it, I have put at least 10 different clutches in it with my HD CSC (testing different clutch kits for South Bend and us if you're wondering why so many clutches have been in it)
I did a 2012 Nismo last week the master is failing on at less than 30k, Not every one fails, But many do.

They are pretty simple to diagnose, If the pedal is falling or not returning all the way after pushing it, Sometimes you may have a little pressure at the very bottom, You've changed everything else and can't get a pedal or get it to bleed and you are NOT losing fluid it is almost always the master cylinder. A lot of times if the pedal goes away you can pump the pedal vigorously with your hand and get the pedal back to some point if it is the master.

A master issue may come and go, A slave issue will almost always be 100% failure.

If your fluid level is down and your pedal wont return (at all) and you see fluid coming out of the bellhousing your slave is toast.