What is Up with These Clutches!?

radensb

It seems like I am always dealing with the clutch in one way or another...

I had both the master and CSC replaced back in February and bleed with GT-R fluid. All was fine for about 6 months, after which, I began loosing pressure in the clutch peddle after 10-15 minutes of driving to the point that I could not shift. If I shut the car off for a few seconds, I would get pressure back for another minute or so. I solved this by flushing the clutch fluid with new ATE TYP 200. The old fluid that came out was very dirty. With the new fluid, the clutch performed great and I had no issues...

...until a few days ago. I am noticing that the peddle is getting soft again after extended periods of not shifting (20 min freeway commute in overdrive). When I shift out of overdrive, the clutch peddle goes down about 75% without resistance and engages at the very end of travel before hitting the wall. If I pump the clutch, I get pressure back and as long as I am pressing the clutch at regular intervals (city driving) it doesn't give me any problems. I am going to flush the fluid out again, but I don't really want to have to do this every few months. So far, it has not left me in a state where I cannot shift, however, it is the same symptoms as before that lead to that state.

I am not racing or being hard on the car, just commuting and the fluid level never changes, so I'm not leaking. Anyone else experience this?

Chuck33079

If you replaced the OEM CSC and master with other OEM parts, it's probably failing again. Put in an aftermarket CSC and your problems will probably be over.

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2011 MB Touring-Sport-6sp-Nav/GTM TT/FI TT TDX/JTran/Kosmic/Eibach/Hotchkis/SPC/CSF/RPS/SoThatsWhereAllMyMoneyWent

radensb

After 8 months and under 10K miles of normal driving? I know the CSC is crap, but it should be better than that!

If the CSC was failing again, why would a fluid flush fix the problem? Why would pumping the peddle temporarily fix the problem? Why would there be no fluid loss?

The clutch is a fairly simple system, but I cant figure out how these problems are happening. All I can come up with is that the fluid is slowly boiling and breaking down to the point of un-usability.

Chuck33079

No, the seals in the OEM CSC are slowly failing. Heat makes it worse, but they are failure prone regardless of fluid used. It's a bad design from the beginning.

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2011 MB Touring-Sport-6sp-Nav/GTM TT/FI TT TDX/JTran/Kosmic/Eibach/Hotchkis/SPC/CSF/RPS/SoThatsWhereAllMyMoneyWent

JARblue

Yes it is, and yes it should. But it isn't, and Nissan refuses to acknowledge the problem as far as I can see. So don't put another OEM CSC in the car. There are at least three very reputable aftermarket options (Z1, Zspeed, Specialty Z). I elected to go with Z1's external slave cylinder

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radensb

If the seals are failing, wouldn't I be experiencing leaks and fluid loss? My fluid level hasn't changed in months.

Chuck33079

Dude. It's a failing master or CSC. It's the most discussed topic on this site. The OEM ones fail. The only solution is to replace the OEM CSC with an aftermarket one.

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2011 MB Touring-Sport-6sp-Nav/GTM TT/FI TT TDX/JTran/Kosmic/Eibach/Hotchkis/SPC/CSF/RPS/SoThatsWhereAllMyMoneyWent

JARblue

Listen to Chuck, dude. The seals are gradually failing. If it's the CSC, when they finally fail, it will be sudden, and you will lose clutch function. Fluid will get all over your bell housing and possibly on your clutch. Not good. With the CMC seals, you will notice the pedal starting to get mushy before they fail.

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1slow370

the master cylinder seal leaks internally there won't be fluid loss it just wont build good pressure, the csc develops a small leak dribbles out a little fluid and sucks in air becoming useless until pumped and then will work for a bit until the leak gets worse and bam gone. replace the csc with aftermarket and do the master at the same time.

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radensb

If it is the most discussed topic here, then there should be a better answer to exactly what is happening. While I agree that aftermarket is the way to go, there is no way consumers would tolerate a $1500 - $3000 repair every 6 months and that leads be to believe that there is another issue here.

A failing CSC would not suddenly work as normal for months of driving with just a fluid flush. Failed seals, as you suggested, means leaking. I don't have this and no fluid is leaving the system. This means one of two things.

1. Fluid is going somewhere else when I press the clutch (not sure how that could be possible, where would it go and how would it get back into the reservoir?)
2. It is breaking down and boiling allowing for comprehensibility.

When I flushed the fluid 3 months ago, with the exact same symptoms, the problem was gone. If the CSC was failing, that would not be the case.


Is everyone here with an OEM CSC getting it replaced every 6 months?

radensb

Ok, master is leaking internally. This sounds more probable, but if that was the case and if the the CSC was leaking, I would see a drop in the reservoir level over time.

jaytirbhaw

not every 6 months, but I would venture to say everyone that drives their Z regularly WILL have the OEM CSC fail eventually, so it won't hurt to replace it while you're ahead of it happening.

If it is just your master failing, you'd still want to replace both, saves the headache

radensb

I agree. The OEM unit is crap and will eventually fail. But being that I just had my master and CSC replaced, and solved this once before with new fluid, I dont think failed parts are my issue. Besides, half of my driving is on the freeway with little to no shifting so its not like im aggressively wearing it out.

jaytirbhaw

That fluid won't give you much improvement for long, If you really feel like its not the master or the slave, i would recommend flushing with some redline fluid, If it still feels like crap it is the master, and yea hate to say it but they have been known to fail that quickly. Which is why no one recommends replacing with the oem parts.

Chuck33079

I'm not sure why you keep arguing. You can try and rationalize things, but at the end of the day you aren't the first person to have your problem. Guess what ended up being the issue for all those other people? The answer has been given to you several times in this thread alone, not to mention the thousands of similar posts on this forum.

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2011 MB Touring-Sport-6sp-Nav/GTM TT/FI TT TDX/JTran/Kosmic/Eibach/Hotchkis/SPC/CSF/RPS/SoThatsWhereAllMyMoneyWent