Does this happen to your 6MT????
#47
12-06-2010, 02:03 PM
#48
12-06-2010, 05:18 PM
Exact same issue, they changed the master cylinder, didn't fix the issue, then Infiniti couldn't find anything to explain this... Finally it started making noise comsistantly, ended up getting a whole new tranny under warrenty, and while they were in there I had the change the clutch with ACT and stillen flywheel. The clucth doesn't stick to the floor, I can launch at whatever RPM I want. No burning no clutch stuck to the floor. When people say it's the clutch delay valve/ orface. I'm not sure this is the issue because it seemed to fix with a new clutch. Anyone have any thoughts, need more info on this CDV (clutch delay valve).
#49
12-06-2010, 06:10 PM
I don't know anything about the CDV. The OP complained that after a few high rev launches his clutch pedal was on the floor and would not come back up unless he lifted it with his toe. Someone told him it was his clutch fluid overheating and he needed better clutch fluid.
I don't think this is correct.
I just looked at my 06 clutch pedal. There is a very large clutch return spring under there. It seems to me (an again, I'm not expert) that this spring is what raises the clutch pedal back up when you release pressure. If the clutch pedal is staying on the floor then either there is something wrong with this spring or something else is overpowering this spring to keep the pedal down. I just don't see how this could be related to boiling clutch fluid. Even if there was no fluid in the system that spring should bring the pedal back up.
I don't think this is correct.
I just looked at my 06 clutch pedal. There is a very large clutch return spring under there. It seems to me (an again, I'm not expert) that this spring is what raises the clutch pedal back up when you release pressure. If the clutch pedal is staying on the floor then either there is something wrong with this spring or something else is overpowering this spring to keep the pedal down. I just don't see how this could be related to boiling clutch fluid. Even if there was no fluid in the system that spring should bring the pedal back up.
#50
12-06-2010, 06:11 PM
I don't know anything about the CDV. The OP complained that after a few high rev launches his clutch pedal was on the floor and would not come back up unless he lifted it with his toe. Someone told him it was his clutch fluid overheating and he needed better clutch fluid.
I don't think this is correct.
I just looked at my 06 clutch pedal. There is a very large clutch return spring under there. It seems to me (an again, I'm not expert) that this spring is what raises the clutch pedal back up when you release pressure. If the clutch pedal is staying on the floor then either there is something wrong with this spring or something else is overpowering this spring to keep the pedal down. I just don't see how this could be related to boiling clutch fluid. Even if there was no fluid in the system that spring should bring the pedal back up.
I don't think this is correct.
I just looked at my 06 clutch pedal. There is a very large clutch return spring under there. It seems to me (an again, I'm not expert) that this spring is what raises the clutch pedal back up when you release pressure. If the clutch pedal is staying on the floor then either there is something wrong with this spring or something else is overpowering this spring to keep the pedal down. I just don't see how this could be related to boiling clutch fluid. Even if there was no fluid in the system that spring should bring the pedal back up.
#51
12-06-2010, 06:59 PM
This is a pretty common issue. It seems like it affects almost all G drivers, crazy how they can get away with not making this a recall. I will say that I have had this problem and it was quite bad last year. Any aggressive shifting around redline would cause the clutch to stick halfway, it even stayed that way for a week or two before I figured out what happened. The car drove fine with the clutch half stuck but it definitely burned the clutch and you could smell it. The problem somewhat went away but would come back when it was really hot out, or when I would do a really long drive. Recently, I was prepping my car for the track and I realized there'd be no way to track the car under these conditions. I went ahead and did the fluid flush with ATE Racing brake fluid and it made my clutch feel much much smoother. The pedal travel itself is noticably smoother and I had no issues at all at the track. While perhaps this is a temporary fix, as it seems as though the slave cylinder is the real cause of the sticking (that is what a service advisor told me at least), it is probably one of the easiest maintainance jobs you can do on your car, it took like 10-15minutes. Give it a shot first.
#52
12-06-2010, 08:27 PM
#54
12-06-2010, 10:44 PM
Registered User
#55
12-07-2010, 09:56 PM
Take a look at this video about launching and the effects on clutch fluid: boiling, etc. This should provide some of the detail in all its visual goriness: http://www.rangeracceleration.com/Clutch_Care.html
That said, I wouldn't just follow the ranger protocol. I would flush the clutch fluid completely.
That said, I wouldn't just follow the ranger protocol. I would flush the clutch fluid completely.
#56
12-08-2010, 08:37 AM
Thanks for the link. I'm at work right now and can't view the video and don't have time to read it all but I'll study it when I get home.
However, with a quick look I noticed two things. First, in these GM cars the slave cylinder is inside the bell housing. This helps explain why heat and clutch dust could get to the clutch fluid. Still not clear exactly how (why would dust penetrate a hydraulic seal that was functioning properly?). Is the G slave cylinder inside the bell housing? Second, as far as I could see there is still no explanation as to why a hydraulic issue (master/slave/fluid) would cause the pedal to stay on the floor when there is a good sized srping attached to the pedal. Again, if the pedal is on the floor this means that something in the hydraulic system is pulling it down against the spring pressure! How can this be? I don't know and I'm probably missing something. Maybe this article will help when I look at it in more detail.
Also, I'm not sure I buy his whole premise. He's saying that he changes fluid frequently and has no problems with his clutch. So he concludes that dirty, water filled fluid is the problem. However, this doesn't account for the majority of drivers who don't have this problem and also don't change their fluid often. So his whole claim seems to be flawed from the outset. Again this is just a quick impression. I'll look closer this evening.
However, with a quick look I noticed two things. First, in these GM cars the slave cylinder is inside the bell housing. This helps explain why heat and clutch dust could get to the clutch fluid. Still not clear exactly how (why would dust penetrate a hydraulic seal that was functioning properly?). Is the G slave cylinder inside the bell housing? Second, as far as I could see there is still no explanation as to why a hydraulic issue (master/slave/fluid) would cause the pedal to stay on the floor when there is a good sized srping attached to the pedal. Again, if the pedal is on the floor this means that something in the hydraulic system is pulling it down against the spring pressure! How can this be? I don't know and I'm probably missing something. Maybe this article will help when I look at it in more detail.
Also, I'm not sure I buy his whole premise. He's saying that he changes fluid frequently and has no problems with his clutch. So he concludes that dirty, water filled fluid is the problem. However, this doesn't account for the majority of drivers who don't have this problem and also don't change their fluid often. So his whole claim seems to be flawed from the outset. Again this is just a quick impression. I'll look closer this evening.
#57
12-08-2010, 08:47 PM
I just watched the video and read the whole thing. I think his theory is full of holes.
1) I still don't understand how clutch dust is getting into the fluid. His contention is that it is getting past the seal on the slave cylinder. How is dust getting past a seal that is still intact enough NOT to allow pressurized brake fluid past it? (I own and operate a tractor with exposed hydraulic pistons on the front end loader. They are exposed to extreme dust, mud, water and dirt. None of that dust and dirt makes it past those o-rings.)
2) If the contamination of the fluid is, in fact, clutch dust I still don't understand how it is possible for that to account for a stuck pedal. If the master and slave can still generate enough pressure to lift the pressure plate, how can the pedal stick?
3) His explanation about water vapor in the fluid is plausible in terms of a mushy pedal or a pedal that won't actuate the clutch. But it does not explain a pedal that stays down.
4) The boiling clutch fluid explanation just does not seem to make sense. As I mentioned before, even if the slave cylinder is in the bell housing...which he says is vented on the Corvette...I still don't see that much heat transfer occurring between throwout bearing, lift fork, push rod and then fluid. And again, even if the fluid boils...why would the pedal stay down...against the pressure of the return spring.
Certainly this guy knows more about this stuff than I do, but he also admits that even the GM experts are puzzled by this issue and clearly Infiniti is too. So I don't think I'm too far off base in questioning his reasoning.
1) I still don't understand how clutch dust is getting into the fluid. His contention is that it is getting past the seal on the slave cylinder. How is dust getting past a seal that is still intact enough NOT to allow pressurized brake fluid past it? (I own and operate a tractor with exposed hydraulic pistons on the front end loader. They are exposed to extreme dust, mud, water and dirt. None of that dust and dirt makes it past those o-rings.)
2) If the contamination of the fluid is, in fact, clutch dust I still don't understand how it is possible for that to account for a stuck pedal. If the master and slave can still generate enough pressure to lift the pressure plate, how can the pedal stick?
3) His explanation about water vapor in the fluid is plausible in terms of a mushy pedal or a pedal that won't actuate the clutch. But it does not explain a pedal that stays down.
4) The boiling clutch fluid explanation just does not seem to make sense. As I mentioned before, even if the slave cylinder is in the bell housing...which he says is vented on the Corvette...I still don't see that much heat transfer occurring between throwout bearing, lift fork, push rod and then fluid. And again, even if the fluid boils...why would the pedal stay down...against the pressure of the return spring.
Certainly this guy knows more about this stuff than I do, but he also admits that even the GM experts are puzzled by this issue and clearly Infiniti is too. So I don't think I'm too far off base in questioning his reasoning.
#58
12-08-2010, 11:18 PM
N80, this is real
N80,
I had this exact problem happen to me this summer and the ranger is right. It occurred on hot days (75+), with moderate stop and go driving. After the car warmed up, 2-3 minutes, the pedal would not come up all the way from the floor, just about 2 inches from the bottom. The clutch would be fully engaged when the pedal would stop, and I could drive in any gear. Pressing the pedal to the floor, it felt like the clutch was not fully disengaging, but the car would shift ok.
Needless to say I did not drive it long like this. I took the car to the dealership, and they told me my throwout bearing was sticking, and wanted to replace my clutch and flywheel due to me wearing the clutch. (they even sited, "lots a clutch dust in there" as proof of my "bad driving"). I thought about it for a while, looked at some diagrams of how our clutch is assembled, and then figured their diagnosis was impossible. If my bearing was sticking near the clutch fully engaged, the pedal would be stuck 1-2 inches from the top of the pedal throw. If my bearing was sticking near the clutch disengaged position, the pedal would stick 1-2 inches from the bottom of the pedal throw, but I wouldn't be getting any power to the wheels.
So I determined the clutch hydraulics were the source of the issue. I returned to the dealership with diagrams, and proved they were wrong, and told them to start my fix by swapping the fluid to see if it was causing the problem. After a quick clutch hydraulic fluid bleed and refill, I have never seen this happen again.
As for why this happens, the fluid absorbs water, but only as a liquid. This lowers the boiling point of the fluid, and when you apply the normal pressure to the system via the clutch pedal, in fluid that's been exposed to too much water (even just from contact with moist summer air), there is enough energy to boil the fluid. The water boils too, and become steam, which does NOT follow the hydraulic principals that allow the master to control the slave cylinder, and the result is a buildup of steam at one end of one of the cylinders. The pedal does not return because steam is between the plunger of the cylinder and the return position. You can hook the pedal with your foot to pull it up, but it doesn't prevent the issue from happening the next time you press the clutch down and release.
Finally, as for the OP's problem, the above has nothing to do with what you are experiencing. You'll need to rev the car higher then dump the clutch to get the wheels to break free. Try 4-4.5k rpms, it always works for me. Its got to have something to do with the organic nature of our clutches, since they have great grip when they are cold. Unfortunately when we add a little friction, expect to get some slip when the 3k rpms turn to heat. An aftermarket clutch and lighter flywheel will also solve your problem. Ultimately, I think when a warm organic clutch grip surface competes with warm, sticky 245mm rear tires, at 3000rpms on a 7500 redline engine, there is not enough torque to break the tires free. So instead the clutch heats up and starts to glaze, letting all the power turn into heat and dust. Good Luck.
I had this exact problem happen to me this summer and the ranger is right. It occurred on hot days (75+), with moderate stop and go driving. After the car warmed up, 2-3 minutes, the pedal would not come up all the way from the floor, just about 2 inches from the bottom. The clutch would be fully engaged when the pedal would stop, and I could drive in any gear. Pressing the pedal to the floor, it felt like the clutch was not fully disengaging, but the car would shift ok.
Needless to say I did not drive it long like this. I took the car to the dealership, and they told me my throwout bearing was sticking, and wanted to replace my clutch and flywheel due to me wearing the clutch. (they even sited, "lots a clutch dust in there" as proof of my "bad driving"). I thought about it for a while, looked at some diagrams of how our clutch is assembled, and then figured their diagnosis was impossible. If my bearing was sticking near the clutch fully engaged, the pedal would be stuck 1-2 inches from the top of the pedal throw. If my bearing was sticking near the clutch disengaged position, the pedal would stick 1-2 inches from the bottom of the pedal throw, but I wouldn't be getting any power to the wheels.
So I determined the clutch hydraulics were the source of the issue. I returned to the dealership with diagrams, and proved they were wrong, and told them to start my fix by swapping the fluid to see if it was causing the problem. After a quick clutch hydraulic fluid bleed and refill, I have never seen this happen again.
As for why this happens, the fluid absorbs water, but only as a liquid. This lowers the boiling point of the fluid, and when you apply the normal pressure to the system via the clutch pedal, in fluid that's been exposed to too much water (even just from contact with moist summer air), there is enough energy to boil the fluid. The water boils too, and become steam, which does NOT follow the hydraulic principals that allow the master to control the slave cylinder, and the result is a buildup of steam at one end of one of the cylinders. The pedal does not return because steam is between the plunger of the cylinder and the return position. You can hook the pedal with your foot to pull it up, but it doesn't prevent the issue from happening the next time you press the clutch down and release.
Finally, as for the OP's problem, the above has nothing to do with what you are experiencing. You'll need to rev the car higher then dump the clutch to get the wheels to break free. Try 4-4.5k rpms, it always works for me. Its got to have something to do with the organic nature of our clutches, since they have great grip when they are cold. Unfortunately when we add a little friction, expect to get some slip when the 3k rpms turn to heat. An aftermarket clutch and lighter flywheel will also solve your problem. Ultimately, I think when a warm organic clutch grip surface competes with warm, sticky 245mm rear tires, at 3000rpms on a 7500 redline engine, there is not enough torque to break the tires free. So instead the clutch heats up and starts to glaze, letting all the power turn into heat and dust. Good Luck.
#59
12-09-2010, 08:09 AM
That's the most plausible explanation I've heard so far. I think there are still some issues with it but I'll think about it for a while.
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