Hey,

I hate to create this thread as there are SOOOOO many threads on this already, but I need an answer to this quickly and I can't seem to figure this out.

Most reports I've heard of the clutch pedal sticking halfway up on the return, has been in warmer weather.

My clutch sticks about just as much in all weather conditions including -10C (15F). It generally sticks during higher RPM shifting/launching. It has also stuck during some lower rpm shifts although it didn't seem to stick as close to the floor. Around Christmas I drained/bled all of the old clutch fluid out and to the best of my knowledge I got all of the air out of the system yet it was still sticky.

After doing a bunch of research it seems like a lot of the reports of VQ's needing new clutch master cylinders is when the pedal will actually stick all the way to the floor, and that people generally have needed slaves if the pedal stuck halfway up in hot weather with clean fluid.

When I told my mechanic of the issue he said that the master/slave are more involved in the pressing down of the pedal, whereas he said that if the pedal wasn't returning all the way that it would more likely be that the pressure plate isn't strong enough. I see no reason for him to lie to me as he had agreed to install a new clutch/flywhel as well as the master/slave cylinder before I described the issue further so he would only be screwing himself out of labor. I however am not exctremely convinced that it is only the pressure plate, because I had replaced the clutch/flywheel before and the issue was still there. I also got the shop to bleed to master/slave cylinder although I'm not sure if they did a thorough job.

Could I please get some advice on this?

 

Does anybody have any suggestions on this? My mechanic is insisting after pulling it apart that it is not a hydraulic issue because it's only having issues going up on its own but I have no idea!

 

sounds like your slave cylinder is leaking. monitor the fluid level before the problem and after the problem.

 

Have you tried adjusting the master cylinder? The plunger has a threaded rod. There's then a "fork" that threads onto the plunger.



Loosen the lock nut, I believe it's a 12mm. And then turn the rod to unthread it from the fork so that it effectively gets longer.

 

No I haven't but I'll mention it to my mechanic.

I received a call from him a couple of hours ago and he told me that my clutch had blown to bits and that there was chunks of metal everywhere! He said that as of right now he doesn't know what's wrong, but that it is going to be longer then he quoted me for because he already spent 1 hour cleaning everything out with brake cleaner. Does this sound reasonably or do you thinking this guy is making it up?

Thanks

 

If your clutch exploded, I think you would have noticed...

But if your pedal was sticking and causing the throw out bearing to constantly press against the fingers of the pressure plate... I suppose it's possible that either the bearing or the pressure plate fingers could have failed. But again... I think you'd notice... especially with bits of metal whirling around your bellhousing.

 

It went quite quickly and smelt VERY bad but I didn't hear anything. I'm going to go have a look tomorrow I know a lot of people who trust this person so I'd be surprised if he was fabricating all of this.

 

I may know what cause the chunks of metal but I don't know enough about clutches. I drove my car for about 10 minutes as it was heavily slipping, and then yesterday I tried to drive it to the shop but couldn't get into gear and ended up revving up to about 3500RPM "in gear" with no motion whatsoever. I'm wondering if this could have caused "the huge f****** mess in there" as my mechanic put it.

 

I had the same problem when i first bought the car (used). I took it to Infiniti and they replaced the clutch slave cylinder. Problem sovled.

 

Thanks buddy! I've decided to replace everything though. FLywheel, clutch, aftermarket clutch pedal/ master cylinder, and the slave cylinder which is most likely the culprit!

 

I have had this problem, for me it was a leak in the clutch line. I had to keep fluid in the car at all times. It finally popped and that was a terrible night for me.... But I would take a look at your slave cylinder, and your clutch line. If its the line buy a metal line.

 

Thanks guitarrocker! Stainless steel line was just installed actually!

 

Had you read more than a few threads about clutches failing you would have discovered that when a slave cylinder fails the pedal falls to the floor, pulling it up by hand will get you to the nearest Nissan dealership. It never does what you describe by hanging up half way....Gary

 

That's why I had created this thread because all of the examples I had heard the clutch pedal will drop and have to be pulled up. With mine the clutch pedal would get half stuck mid way and would either have to be gently pulled up with the foot, or it would snap out.

Upon taking out the clutch pedal the spring was found to be faulty, although this most likely only accounted for a small "sticky" region near the top of the clutches travel. Based off of the how it felt, I think that a lot of the reason that I was having issues was because the stock pressure plate wasn't strong enough to fully engage the gears at high rpm. This sticking clutch pedal was happening last time I drove a brand new clutch off the lot, so I know the the pressure plate is not solely the cause of the problem.

I am thinking that the stickiness still probably had something to do with the slave cylinder which I swapped out, but the problem could've also because fixed by installing the wilwood master cylinder with a larger reservoir.

Regardless, this just proves again like everyone else say online do these things in order until there is no more issue: flush out you fluid with DOT4 ensuring that the system is properly bled, install a stainless steel clutch line, replace the slave cylinder/master cylinder.

Thanks guys

 

This is actually much more common than you think and is caused by a weak master cylinder.

Basically what is happening is the seal inside is leaking internally on the up stroke and causes the pedal to hang and not return all the way to the top. When the seal begins to get weak, because it is a cup style seal, it will only seal when there is pressure on it, when you are on the way up there isn't as much pressure so it will leak by the seal and back into the reservoir instead of pushing the pedal back up.