Keep this updated, My guess is it will work for awhile then you'll be back for a master cylinder replacement.

So am I correct in assuming that if we change our fluid from DOT3 to DOT4 we'll avoid this issue???

What are the hazards of leftover DOT3 mixing with DOT4 if we attempt this, is there an incompatibility?

I get the feeling I'm reading too much into this and the OP actual problem is CSC or MC but I'm not a practicing mechanic.....

All brake fluid is synthetic.

Dot 4 has slightly higher wet and dry boiling points. Both are compatible with one another but not dot 5 (albeit dot 5.1 is also compatible with 3 & 4, but not 5).

IMO, at a minimal, dot 4 should be used in any high perf vehicle.

Lazy to read past post. Any particular year model does this problem occurs?
or what Date of manufacture? TY.

Took 5 days because I dropped it off Friday 20 min before the service department was closing so they did not get to look at it till Saturday, and of course Saturday the clutch pressure was fine (magic I know) so they let it sit until they can find what the problem was, Sunday was day 3 and they were closed so Monday day 4 was really the 2nd day they looked at it and the pressure was fine again. They couldn't find any leaks of course and didnt know why it lost pressure so finally tuesday they got the bulletin and informed they will be replacing the fluid & to come get it the next day (weds). So yea kind of a long hassle I'm just hoping it was really that and not the cmc warranty or not

I might be willing to change my fluid now before I have any problems. Let us know how it works out. I'm not having any clutch issues now but one never knows....I'm half expecting it but since my car has 12K miles on it (2009) I hope I have a little while before I have to get underneath it.

Wasn't thinking when I typed that lol.

Yes dot 5 is a big no no.

The difference between dot 3 and 4 is negligible for a street or street performance vehicle. Unless you are going to track it, if you have DOT 3 in I wouldn't go run out and change it just because it is DOT 3 (your not going to boil it on the street or spirited driving). Also I believe the viscosity is different between the 2.

I'm at 6,700 miles and had to do it :/

Just an update on my experience with taking my Z in and the service department performing the service tech. Bulletin GTX fluid swap out.... It's been 2 weeks and the moving clutch engagement issue has not re-occurred. I was skeptical and it still might go bad, but it's performing fine right now. Just FYI

Does anyone know if black deposits (almost like a fine black silt) in the bottom of the clutch fluid reservoir is a sign of seals wearing out on my master or slave cylinder? I am running the stock dot 3 fluid. Flushed about 6 months ago.

:iagree: Is the CSC an issue with later models?

Hi Mandingo,

The silt could either be decay from the black hose connecting the Clutch fluid reservoir to the Master cylinder or as you suspect, pieces of the O rings and/or the seals in the master cylinder or the CSC.
I'm not a mechanic by trade so those are my best guesses. I did watch a video the other day when a guy bled the old fluid out of his G37 clutch line and the mechanic was wiping out the black silt in the reservoir that you described, he didn't make any comment about it's origin. I don't know if it's normal wear and tear, the clutch does get a lot more sloshing around than the brakes so the fluid could theoretically move from top to bottom on a regular basis.

I found the video again: http://www.youtube.com/watch?feature...&v=1A9fsdoAngI

Hi Akmcmahon,

In this forum I've read about 2013 on down having the CSC failure within 7000 miles and some at 20 or 30,000 miles and some having that many miles with no failures. I detect no pattern and theoretically, because "race car" then power train components should not fail within the boundaries of their use (capability of the engine) etc.

It is normal to get black silt in the reservoir. This is very fine clutch debris that works its way past the seals from the internal slave (CSC). They will all get it sooner or later.

We recommend flushing the system at least twice a year with the stock slave or our HD slave.

Thank you Joe and Fountainhead. I saw the recent TSB about replacing our dot 3 fluid with the dot 4 brake fluid from the GTR. I've ordered some and will flush this weekend. I'll just keep a closer eye on it now :tiphat: