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BLACK/BROWN CLUTCH FLUID!

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AugustusCaesar

AugustusCaesar

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You use decent DOT4 brake fluid. Do not use DOT3 or DOT 5 BTW. I wouldn’t let my dealership do it.

Definitely drain that brown crappy Nissan DOT4 & refill with MOTUL. Motul RBF600 is like $15 a bottle. Higher boiling point. Well known in the 360Z and Infinity G37 community for years.
You can either open the port on your slave and put a tube on it, then add fluid from the top. I use a vacuum brake bleeder at the slave end and add fluid until it runs clear. Or get someone to pump the clutch instead.

Here’s some posts and someone else’s how to:
Change your clutch fluid

It used to be the Clutch (350Z/370Z) was a CSC (internal to the tranny) which is way worse. Nissan fixed that on the RZ34. But good clutch fluid (DOT4 Brake fluid) is a must as it is hydrophilic (attracts/loves water) even from the humidity in the air. I owned a 370Z for >7yrs so I learned about this… if the dealer put in their clutch fluid, it was dirty & dark brown (cooked) in 10K miles or less.
I also owned a 370z for years. Had to get the CMAK early on in my ownership too.

I have a sport model so I don't have the lock and unlock option in the MyNissan App. Or GPS.
 

alienpoker

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I also owned a 370z for years. Had to get the CMAK early on in my ownership too.

I have a sport model so I don't have the lock and unlock option in the MyNissan App. Or GPS.
I Meant to say “Well known in the 370Z and G37 community…”
Sorry if you knew all this, I thought you were asking the best way forward on clutch fluid changes. I can only assume the clutch fluid has cooked, but hard to believe it would in 8K miles. I guess the 3.0 twin turbo engine runs way hotter than even the 370Z Nismo.

Anyways, the thread may prove useful if someone has the same problem in future.
 
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AugustusCaesar

AugustusCaesar

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What is the car’s born on date? ‘23? fluid is dot4 and takes on water & becomes contaminated faster than dot3 - age matters Just as much as milage.

The 2nd gear grind is common and more than likely from the synchros. How does it shift for the other gears?

if the car is 2 going on 3, i would change the fluids. The brake fluid change as well - it’s probably past due or soon to be.
Just got back and checked it was built June 2024
 

alienpoker

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HOW did you check the fluid, and only get a bit of it? Siphon tube?

Step 1 is CALL THE DEALERSHIP AND VISIT THEM ASAP. Go full-Karen.

Since your post hamstrings us by saying you can't go to the dealership, you can do the following;

- Siphon some of the tranny fluid out.
- Find a reputable oil/fluid analysis place. (I use Blackstone Labs for my engine oil. No idea if they analyze tranny fluid.)
- Get report back that will tell you if there is babbit or contaminants in the oil.

If there IS contaminants or bearing material, you are going to the dealership anyways. Probably during a snowstorm, as it is fast approaching.
Blackstone do trans fluids. I’ve just been looking to do some 6mo analysis, from my first oil change. I’ll only do the std oil tests, but std tranny fluid testing is the same price. In fact they do std analysis of:
  • Transmissions
  • Gear boxes (differentials, transfer cases, etc.)
  • Power steering reservoirs
  • Generators
  • etc…
BTW- The 370Z 6sp mt always had a clunk 1-2. Less for 2-3 and nothing after that. I thought Nissan re-engineered the synchros for the RZ34 to help solve the 6sp issues. But it shouldn’t be grinding, if it does then double clutch for now. Definitely do the trans oil analysis & then get it checked out when you have the data. Do it now so you stay within the warranty. That’s my .02
 

bpeckham

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What color is the clutch fluid supposed to be? I seem to recall earlier checks where it was basically clear, but am I remembering correctly? I was checking everything yesterday and this thread was stuck in my mind. My clutch fluid is slightly brown as well. Flashlight providing illumination.

1000058751.webp
 
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AugustusCaesar

AugustusCaesar

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What color is the clutch fluid supposed to be? I seem to recall earlier checks where it was basically clear, but am I remembering correctly? I was checking everything yesterday and this thread was stuck in my mind. My clutch fluid is slightly brown as well. Flashlight providing illumination.

1000058751.webp
Suppose to be light yellow. Nearly clear.
 

bpeckham

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Suppose to be light yellow. Nearly clear.
Mine's a 2023, built in December 2022 and purchased in April 2023. I've never serviced the clutch fluid so far, maybe next oil change I'll have them replace it.

@Administrator here's another double message. No error this time. Just showed up twice.
 
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AugustusCaesar

AugustusCaesar

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Mine's a 2023, built in December 2022 and purchased in April 2023. I've never service the clutch fluid so far, maybe next oil change I'll have them replace it.
For reference, mine is a 2024 built in June 2024, bought February 2025. I also haven't changed it.
 
 






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