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CMC Failure?

Old Feb 16, 2018 | 02:22 PM
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Unhappy Clutch Master Cylinder Failure? Clutch pedal to floor..

My clutch pedal has no pressure and most likely the culprit is the CMC. looking at my options and leaning toward the ZSpeed CMAK w/ Southbend stage 2 17lbs flywheel and quiet disk or JWT set up with their flywheel. Also I want to get the RJM pedal with the upgraded CMC. Any opinions?

Car has 45,000mi

Last edited by Calg37USMC; Feb 16, 2018 at 08:32 PM. Reason: No love.
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Old Feb 16, 2018 | 05:37 PM
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Could be the master or slave. Not enough information provided.

Spelling out the words in the title may attract more responses.
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Old Feb 16, 2018 | 07:52 PM
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My pedal is to the floor, fluid was low recently switched over to rbf 600 within 1500mi. Can’t get clutch to engage to switch gears. Is there a way to edit thread title? Still learning...
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Old Feb 16, 2018 | 08:21 PM
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If you click on the Edit Post button, do you then get an advanced button?
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Old Feb 16, 2018 | 08:33 PM
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Originally Posted by slartibartfast
If you click on the Edit Post button, do you then get an advanced button?
Thank you!
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Old Feb 16, 2018 | 09:27 PM
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I hate reading about this failure in the 6mt.

I swapped to RBF600 @20k.
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Old Feb 16, 2018 | 10:35 PM
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Originally Posted by Lego_Maniac
I hate reading about this failure in the 6mt.

I swapped to RBF600 @20k.
Have you had the system fail on you? It’s a flaw from the beginning and the latest 370z has the problem still. Nissan should fix this flaw. But do you guys have any suggestions on the options I listed? I will be purchasing soon I’ve done research and that’s what I’m getting is the best options.
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Old Feb 16, 2018 | 10:39 PM
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Originally Posted by Calg37USMC
My pedal is to the floor, fluid was low recently switched over to rbf 600 within 1500mi. Can’t get clutch to engage to switch gears. Is there a way to edit thread title? Still learning...
Your symptoms actually suggest the slave failing, not the master. Unless the master has an external leak, typically there's no indication of fluid loss with failure. Instead, the piston that's supposed to be generating pressure when pumping fluid is instead pumping through the fluid without any pressure.

A fail[ed] slave will indeed result in fluid loss. The main seal will fail and eventually you pump all the fluid out. The fix is $$$, involves dropping the trans. Depending on mileage is also a good time to replace the clutch entirely.

Replacing the master at this time is also a good idea.
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Old Feb 16, 2018 | 11:23 PM
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Originally Posted by Calg37USMC
Have you had the system fail on you? It’s a flaw from the beginning and the latest 370z has the problem still. Nissan should fix this flaw. But do you guys have any suggestions on the options I listed? I will be purchasing soon I’ve done research and that’s what I’m getting is the best options.
No, I haven’t had any failure, but I’m certainly conscious of it, and I’m at ~52k.

As for replacement, I’d just go OEM, but mostly because it would be a warranty repair for me and I’m not making much more than stock power.

Agreed though, it does seem like a weak link, hence my early clutch flush.
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Old Feb 18, 2018 | 01:52 PM
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That's classic slave cylinder failure, pretty common on Zs and Gs. Get an HD one from ZSpeed or Z1 makes a concentric slave cylinder delete. Replace the master while you're at it since the contaminated fluid might have screwed that up too and the failing master might kill your new slave. If you got the $$$ might as well replace the clutch since you're 95% of the way there on labor to get at the slave cylinder.
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Old Feb 18, 2018 | 11:28 PM
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What you listed in the original post is exactly what I just installed after my CSC went out.

South Bend Stage 2
ZSP Steel 17lb flywheel
Quiet Disk
CMAK
Motul 5.1
RJM pedal assembly and CMC

Drives very similar to stock. Revs a little quicker and it's not that noisy at all. Definitely a great upgrade and no longer have to worry about the factory CSC crapping out.
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Old Feb 19, 2018 | 08:58 PM
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The oem part number was superseded. I wonder if they improved it. Z1 makes a HD oem slave for about $300 if u don't wanna do the delete. They reported that it worked for pretty long
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Old Feb 19, 2018 | 09:02 PM
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Here's another tip exedy does not make the oem replacement for the g37 anymore. They're sourced from a company called luk. Rock auto sells the oem replacement disc n pressure plate by a company called sachs. Also for the g35 the factory would sell the disc and plate separate but no not with the g37 the factory sells both together only.
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Old Feb 19, 2018 | 09:03 PM
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Here's another tip the online sellers including dealers like z1 mistakenly list the g35 and g37 as the same clutch disc and plate it's bull****
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Old Feb 19, 2018 | 09:20 PM
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I think I’m going with ZSpeed CMAK kit which requires no adjustments which the Z1 kit calls for.
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