"Possessed" clutch issue???

[backtotintops]

Since getting the car I have driven many miles on the street and love it!!! Maybe 5-7 times I smelled the burning clutch smell and maybe only 2 of those times were in situations where I was getting on a trailer and possibly riding it a bit and might expect that. The other times it was totally uncalled for and was disturbing to me.

Then recently at NJMP, I took the car out on the 2nd day with my student and the clutch seemed weird…it did not have full travel and was impossible to toe heel in to 3rd with out some grinding as I tried to find third???…I have never had to find any gear before??? and then I backed out…this seemed very odd and I double clutched the rest of the session which worked fine and was going slow anyways. This was strange and unnerving but when I got in the next session alone and set out to go fast everything seemed fine and no problems rev matching.

So now the car sits for a long time since I did not have time to clean it and I won’t drive it on the street with rubber all over it. So 2 days ago I washed it and took it out for the customary dry out speed run and the exact same thing…the clutch felt weird and really had about a third less travel but still worked. I did the 10 minute run and somewhere in that time it came back to normal. After a final burst of maybe 120 then an exit off the highway to stopped at a red light…I’m on a slight incline so foot on the brake and foot resting lightly on the clutch pedal in the normal position….YOU WILL NOT BELIEVE THIS BUT…the freaking clutch pedal MOVED ON IT'S OWN that third of the way down…I DID NOT PUSH iT!!!!!!!!!!!!…I know you all think I’m crazy but that’s what happened. I felt it move under my foot. No change in anything else...just idling at the light.

I drove it a mile back to my garage and it still was in the down position. The picture attached does not really show it well…it is below the brake pedal and is normally slightly above the brake. After taking the picture I was pushing it in and out attempting to measure the reduced travel and it seemed to pop back to normal????

Both times this seemed to start was after sitting overnight or a week.

Does anyone have a clue on this one???

[90503]

I'll take a few guesses, perhaps some things you could look at...

.....Are the brake and clutch reservoir one and the same on the Z/28?....If so, could be fluid level????...Maybe time for a separate reservoir...

....My clutch pedal had a mind of it's own a few times when using "Launch Control"...pedal stuck to floor, clutch smelled...Could be a "mode" thing on the Z/28..?

....Camaro manuals have a common need to warm up a bit or they might grind...

Basically I have no idea....It could actually be possessed....lol....Good luck....

[wakespeak]

Sounds like air in the system to me or possibly clutch dust interfering with things. I also don't think the DOT3 fluid is up to anything beyond daily driving. The separate reservoir for my SS is a necessary mod IMO. The clutch action was much better (less spongy) with DOT 4 and you can eventually get the clutch dust out of the system with enough times changing out the reservoir.

[McRat]

Here's what I learned when tracking the M6 versions of the 2011 CTS-V's -

If you have traction control or SC on, you risk damaging the clutch if you try to force the issue. It won't back the throttle down.

Now, more importantly. Ever since the LS1, the hyd clutch system has been flaky when abused. Heat from the clutch boils the fluid and the pedal engagement point starts to move towards the floor until you have no clutch pedal left.

You need to bleed your clutch using race fluid. Problem is, at least with the early cars, there is no provision for bleeding. They make a throwout bearing with and external bleeder for the aftermarket.

NOTE: I'm not sure this applies to the 2014 LS7, but I believe it does. If the pedal goes all the way down, your clutch is probably toast.

[backtotintops]

So since this seemed to only happen after hard track runs it is possible that the fluid boiled in the clutch only and has created an air pocket that when in the right position allowed the pedal to travel down on it's own?

I believe the brakes and clutch are together and we put in SRF and bled all corners but did not know to bleed the clutch?

and this happened while the car was warming up so it might also be heat related?

Why the burnt clutch smell the other times? when there was no pedal issue?

The pedal only lost about 30 of the top travel and still engages the clutch when this happens and the car is driveable.

[backtotintops]

Originally Posted by McRat

If you have traction control or SC on, you risk damaging the clutch if you try to force the issue. It won't back the throttle down.

explain? I had ptm3 on when I first noticed the problem and had problems going in to 3rd on the track and the other day on the highway no ptm mode at all.

[McRat]

On the Caddy, it would use the rear brakes to stop wheelspin, so you could smell the clutch frying if you try to spin the rear tires with TC/SC on.

ALL OFF is the safest on the equipment, but perhaps less safe to the body panels.

[McRat]

DISCLAIMER - Even though I put in for my car in February, I do not have a Z/28. My experience is based on LS1 Fbodies, LS1/LS6 Corvettes, and LSA CTS-V's with manual transmissions.

My experience might be invalid for LS7's.

I would search the Corvette forums for information about clutch issues with the LS7. While there is no guarantee it will apply, it probably will.

[Novie LE]

I dont see how leaving traction or stability on would affect how the clutch works in any way shape or form. To me it sounds like the fluid is shot or the cylinder is on it's way out. Does the clutch come back up on its own after you use it or is the travel still limited? Does the pressure changed if you pump the pedal?

[2SSRS@Gen5diy]

The Z/28 and the SS use the same clutch, and there known to have this problum, here is the fix, IMO.

http://www.camaro5.com/forums/showthread.php?t=34085

[McRat]

Originally Posted by Novie LE

I dont see how leaving traction or stability on would affect how the clutch works in any way shape or form. To me it sounds like the fluid is shot or the cylinder is on it's way out. Does the clutch come back up on its own after you use it or is the travel still limited? Does the pressure changed if you pump the pedal?

If the TC/SC chops the throttle instead of using brakes, then it's no issue. If it uses the rear brakes, you must slip the clutch harder to try and accelerate. This increases fluid temps in the throwout bearing, boils the fluid, then sucks in dirt when the fluid cools.

As long as you don't apply enough power to spin a tire, there is no effect on the clutch. But if you try and make the tires spin when the brakes are trying to stop wheelspin, you can hurt the clutch.

Out of all the CTS-V M6 cars that GM brought out to Spring Mountain, none of them were still in operation at the end of the day. GM had instructors riding shotgun who were not letting you turn off the TC/SC.

[backtotintops]

Originally Posted by McRat

If the TC/SC chops the throttle instead of using brakes, then it's no issue. If it uses the rear brakes, you must slip the clutch harder to try and accelerate. This increases fluid temps in the throwout bearing, boils the fluid, then sucks in dirt when the fluid cools.

As long as you don't apply enough power to spin a tire, there is no effect on the clutch. But if you try and make the tires spin when the brakes are trying to stop wheelspin, you can hurt the clutch.

very interesting...The first day I brought her home I have a 4' concrete incline at the head of my driveway and it often has sand on it and as I was going up the rears spun a bit and I backed out and then tried again and another spin and it was hard to get up...very strange???...but maybe this explains it...I am sure that I had no ptm mode on only the "touring" button was lit....AND..I smelled the clutch so I think this theory explains the smell and maybe boiling the fluid???...but I don't think it can be boiled in 15 seconds like that?...so I think this explains the smell and the thread with link and video explains the possible pedal issue.

I just went for a 20 mile run and it happened in the middle twice in that the travel was 30% shorter and I pumped the pedal and it came back up. So boiled factory fluid INSIDE the clutch that never circulated to the Castrol SRF that is in the rest of the system???...or this makes no sense and it is just residual air trapped in the clutch from boiling the factory fluid that has never been purged?...would an air pocket cause partial pedal loss and come back after pumping?

Would adding a reservoir (like Ofer did in that thread) void the warranty? Seems like a cheap and easy fix???

ps...stopped by the local dealer and the service manager said there had been a few tech bulletins about the clutches in new Camaros...my guy was away this week so I will bring it in to them next week and see.