370Z clutch line restriction

Zat_Zuma

I've been working with a vendor on the 350Z forum to provide a solution for the Secondary Clutch Slave (CSC) fitting problems with the pressure plates the vendors are providing for our 370Z's. If you have a close look at the CSC's and how it fits and works on some aftermarket pressure plates, you can see the stock fitment is less than ideal. It has been my experience that the CSC's will eventually fail and cause all sorts of problems. I had my fair share of grieve with my 07 HR and CSC failures.

As part of my research I've taken some pictures of my 370Z clutch line layout and disassembled the clutch line block to discover there is a restriction orifice in the block that may cause hydraulic failure with enough heat and cycles. The clutch line is roughly 7 mm ID and the RO is roughly 3 mm ID.

The other difference between a HR and VHR is that the Master Clutch Cylinder is shorter in the 2009, compared to the 07/08 HR's. Other than that the clutch line layout is identical and so is the CSC.

More info and pictures to follow once I get the new CSC kit and clutch line delivered. I will also be installing a new flywheel and clutch from this vendor as well. If all goes well, I hope that they will become a vendor and offer this package to our members here.

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[B]2009 & 2017 370Z Touring Sport Autos SOLD

fstrnldr

so drill out the restriction or stop by the auto parts store and ask for a 10mm brake line union. If you have to have a piece with the mounting tab i can find you a Toyota part number for one. Nissan probably uses one as well but i don't know the Nissan platforms as well as the Toyotas.

Zat_Zuma

Not as easy to drill out the restriction. Not enough material to ensure a proper seal with the flare connections on the clutch line.

Haven't measured the connectors yet to know what size or thread they are yet and yes, it would have to be a brake line type union with the proper flare connection fittings to prevent leakage.

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[B]2009 & 2017 370Z Touring Sport Autos SOLD

fstrnldr

They will either be 10mm or 12mm they are "measured" by the wrench size used on them. I'm guessing 10mm by the rest of the clutch system. and like i said hit up and auto parts store and ask for a brake union fitting.

BRAKELINEUNION - Dune Buggy Parts, Sandrail Parts, VW Parts - MooreParts.com something like that.



90412-10144 Toyota part number if you must have the 6mm hole for the mounting tab.

'10Anamoly

I believe the Z1 and GTM clutch lines eliminate this section of tubing completely so shouldn't that restriction be gone if you upgrade the clutch line?

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fstrnldr

I don't think either of those lines eliminate that potion. That is actually located inside the wheel well behind the rear fender liner.

Zat_Zuma

I guess I should update this post.

I found that the orifice block available @ Courtesy Nissan is the larger orifice block and is now installed on my car. It is the one that the 2006 350Z uses. Part # 30859-Z33002. I also drilled out the one on the 370Z to 1/8" and it looks like it should work just fine, as well.

The clutch line from the frame to the transmission is one I had made locally. The flare fittings are 10 mm in size. I had it made with stainless line at a length of 15" (stock is 13") The extra length gives a bit more clearance from the header and should provide less heat soak. Plus I also triple wrapped the line with insulation.

So far, no problems.

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[B]2009 & 2017 370Z Touring Sport Autos SOLD

L33T Z34

I replaced the clutch restrictor (dampener) with a Dorman 3/16" brake line female to female union, part number 785-438. The union has ~3mm ID and the Nissan restrictor is ~2mm ID. Nissan's specially machined clutch restrictor, called a "connector", is part number 46364-4P000.

modme

So what difference has it made in the clutch feel?

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DOOMMONKEY777

Wow. Amazing find pal +1

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Zat_Zuma

No more delays in clutch release as it's instantaneous. Clutch pedal feel is solid and firm throughout the pedal stroke.

I've also upgraded the clutch and pressure plate to a Southbend brand compliments of Joe @ Z Speed Performance

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[B]2009 & 2017 370Z Touring Sport Autos SOLD

N0SL3N

Do you have a link to the parts you used?

Also this is located inside the drivers side wheel well?

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juld0zer

is this 'restrictor' only on the 2009-2010 models?
I have a 2011..

L33T Z34

No, this restrictor is on every model year, '09-'14. Its even on GT-Rs.
Its only a $4 part. Install it when you do your next clutch fluid, plastic POS CSC and/or clutch change.

juld0zer

but... the R35 GT-R has no foot operated clutch?

The same part is also used on various auto trans Nissan models.
I'm guessing it could also double as a brake line coupler and that's where it might be used on the other cars.

If i'm cracking the lines open i'll be replacing it with a braided stainless one for the consistent pedal feel. But i don't enjoy the idea of cramped work space (no hoist) and brake fluid spewing. Maybe i'll just drain all the fluid first hmmm