Alright, first and foremost thanks for reading.


The Story:
I have an 08 Sport Coupe. I get up Monday morning, cold start her, after about 3 minutes of the car running I go to shift her into gear. Shift into first and then the pedal doesn't come back up; it stays on the floor. I started rolling out of the garage, so now I'm like **** I need to put her back. Attempt to shift into reverse and it won't go anywhere. I wind up pushing it by my back gate until the tow truck comes. Take her to the dealership. They get back to me later that day and tell me that my fluid was gone but they didn't find any leaks and everything checks out but they want to keep it over night and run some tests.

The next day they say everything still checks out and I can come get her. We go fo a test drive and I immediately notice that my pedal is a lot spongier than before. The service guys response is, "its self adjusting and just watch it over the next couple of days, it could also feel softer because you have fluid now and you didn't before". Sounds like bs to me and I'm thinking they need to replace either the clutch master cylinder or slave cylinder, but its warrantied so I'm like f*** it, I'll just bring it back. He's also telling me that they are thinking my clutch is starting to go bad. I leave get about four miles away and the pedal hits the floor!!! I turn around and even though I have to kick all the way to the floor, she shifts into EVERY gear. There was no slipping and no elevated RPMs when throttling (the usual signs of a burnt out clutch).

I get back, explain, they check it out, and they keep her. The next day he tells me that they decided to go on and replace the master cylinder. "Then we will want to run a number of tests afterward." Of course my question is why not do the slave while you're down there? "We'll do that too if we see leaks or a problem." He then proceeds to explain to me how they still think its the clutch. "The heating of the pressure plate is causing a loss in pressure and affecting the pedal." I'm like wtf!!!??? Here's where we get into a dispute. If it was that bad, when the pressure plate heated up it was loose grip on the clutch disc, essentially disengaging and I would see the rpms increasing. That's not happening. But I am to believe that the clutch is going out and although there is no slippage and no elevated RPMs, its some how transferring this lack of pressure through the throw-out bearing, slave cylinder, and master cylinder...all the way to the pedal and causing it to hit the floor (and the hydraulic fluid was full when it hit the floor the second time). That makes absolutely no sense to me! BTW: The mileage on my car is 49800 roughly. I bought a car and found out on the way home that the clutch was burnt out. Engine spun up to 6k rpms to get 2k rpms power, but that didn't affect the pressure in the pedal at all.

The Question(s):
Am I wrong and could the clutch be going bad, causing this situation...even though there are no tell-tell signs of it going out?

Should I be concerned that they are purposely trying to burn my clutch out with all of these tests that they are running?

Has anyone experienced their pedal going to the floor, and if so what was the cause and resolution?

Again, if you took the time to read all of this I appreciate you!

 

I doubt they are trying to purposely make the clutch go bad, but I do think that whoever you are talking to is not so experienced. I would escalate politely and ask if you can talk to the service manager (or GM if you are already talking to the SM) to make sure they hear your position.

I agree that it would make sense to replace the master and slave. It sometimes is hard to find seal leaks, which I suspect this might be. That said, they should be able to find the *location* of the leak, what with all the fluid that should be present.

This is the only argument in favor of what they are saying- *if* the fluid boiled as a result of excessive heat, you would get this effect and you would not find a puddle of fluid dripping out of the bellhousing. But I would, like you, expect there to also be a slippage issue. It is possible there's another heat source near the fluid line causing it to boil (like a heat shield coming off a header, for example).

Again, I doubt there's anything sinister going on here. Give them another chance to fix it. If it's under warranty still (in service mileage is what matters). You still might want to talk to a Manager to voice your concerns, but don't be disrespectful about it. You'll get farther that way.

 

This is a commonly known problem for our stock concentric slave cylinder to go bad! They'll need to drop the tranny to see what the problem is. Absolutely has nothing to do with your clutch and if your clutch was slipping you would know and def won't assert your clutch pedal. That guy is a fool and inexperience for sure.

 

Well there you go. I still think you should escalate *politely*. No reason to get mad.

 

Ashmostro and Weiboy thanks for the insight! Do you know if there are any TSBs about the Clutch slave cylinder?

 

I didn't see anything about this in the TSB forum. Weiboy, you said that this is a commonly known problem. Is there any documentation somewhere that I can print out to help with my case when I go ask them to replace the slave along with the master???

Thanks!

 

you can search all the TSBs here: Infiniti Publications

 

Run a search on this, you'll find plenty of folks here that had this issue but I doubt they have a TSB for this. This problem is also well known for the 350Z hr.

One way to remedy this would be to buy a metal concentric slave cylinder. Our stock one is made out of plastic and would fail at some point.

 

They decided to replace the Master Cylinder. That was done on Friday. I test drove it and the pedal did feel smooth but not spongy. I only drove it for a few minutes to show them a rattle I was getting from my rear woofer. They are replacing it while they have the car. I should get her back later today, hopefully everything is well.

 

It's a whole lot easier/quicker to replace the MC than the CSC. Good starting point I suppose. If the problem returns, then they'll probably replace the CSC. To do the CSC, the trans has to be dropped which involves also dropping the exhaust, driveshaft, etc... Many more labor hours than just swapping out a MC and bleeding it.

How many miles on the car?

If/when the clutch does actually get replaced, go with the heavy duty CSC.

 

There's just under 50k in mileage. When they said that they were going to do the master, I did ask why not do the slave as well (not knowing that the slave was in the tranny). When he responded, "well we have to drop the transmission...", it instantly hit me...you don't want to do that if you don't have to. JSolo, I completely agree with you. I'm sure they've already put 8-10 hours of labor into her already. So, if you have a suggestion for a CSC please pass it along!

 

This is what I had in mind

Nissan 350z 370z G37 G35 heavy duty CSC Concentic clutch slave cylinder

 

Ultimately what wound up happening is they replaced the CMC. I drove it for about a month and then the pedal hit the floor again. I asked them to do the CSC, they kept mentioning the clutch. My fear was that they were tunnel visioned on the clutch and were intent on saying that was the failure regardless. The service rep kept telling me that the tech is sure its the clutch and even consulted with other techs. For those with the warranty, you know the CSC is covered but the Clutch is not. I was just about to have my car towed away, but the I talked to the Service Manager. He explained everything to me in more detail that the original service rep and convinced me to gamble with them. He then told me that even if it became an issue that wasn't warrantied he would give me 20% off labor and parts!

The next day they called me and told me that the CSC/Throw-out bearing was completely fugged and leaking all over the place. Service manager for the win as they could cover my work under the warranty and by the way there was PLENTY of meat left on the clutch. The original service rep called me later to give me another update and in passing said, "yea the tech was wrong." I recall him being SO adamant about backing his word before then. All in all it worked out and wound up being what I originally (and you all agreed) thought it was. I'm really glad I talked with the Service Manager.

 

Are you still covered under factory warranty? Or just drivetrain? I thought the CSC wasn't covered at all.

 

Did any fluid get on the clutch plates? Sounds like they kept in the existing clutch right?