: Anyone using a Z06 clutch? Who's experiencing clutch hydraulic issues?

02-24-07, 02:31 PM
I've been using an LS6-Z06 clutch and the TPIS spacer for about a year now. For the first 5 months or so, everything performed flawlessly. I was surprised I had no problems lugging around a 3800# car with a stock Z06 clutch, but the only difference I noticed was a lighter pedal feel.

Then one night during a brief high-RPM pass through a few gears, the clutch pedal sank to the floor. I picked it up with my foot and noticed how the engagement point had moved to nearly the end of the pedal's travel. When I got home, I checked the clutch reservior and found it almost bone dry. I filled it back up and drove it around for a while, and the clutch travel and firmness returned to normal.

Since then, several related issues have popped up. When my car is cold, the clutch pedal feels light and is slow to return, almost as if it has some air in the line. Once the car starts moving, firmness returns to normal. After I wind it up to 5500+ RPMs, the pedal will firm up even more and engagement point changes again.

I want to think this problem is two-fold: one is definitely a hydraulic issue, either a faulty slave cylinder or cooked fluid. The other problem lies in the stock Z06 pressure plate... I'm thinking there was a batch of bad Z06 pressure plates with weak spring pressures that only exhibited this problem under high RPMs. Am I right here?

I'd like to swap this clutch out with either a known-good LS6 clutch, the stronger LS7 unit, or maybe something aftermarket like the Spec S2. As I understand, the LS2 clutch needs another spacer along with the LS2 flywheel, it needs to be balanced, and the assembly is actually heavier than the LS6-Z06 pair.

02-24-07, 10:53 PM
It might just be air in the lines. If it was nearly dry then it may just need to be bleed.

02-25-07, 04:03 PM
I had a problem with the stock clutch. The reservoir was dry, my dealer fixed it under warrenty. I now have a Z06 setup and have not had a problems.

02-25-07, 04:44 PM
I heard something about the fluid and that there is an adapter for it. Here is what was offered to me:

'While they have the trans out, it's a mega super install and allows you to bleed or change the clutch fluid without having to pull the trans. The clutch reservoir is so small on these cars the fluid gets dirty and gunky very fast. I had the fittings made, they are V specific. If your interested, they cost $90 delivered.'

I guess that's your problem!

02-25-07, 06:22 PM
I would be investigating where your clutch fluid went in the first place. If the hole in res. was exposed and you refilled it with fluid, you have air in the system. PIA to drop the trans just to bleed it. If you going to do it, I think ctsvflorida is describing a remote bleeder a friend of mine had made for his v. He mentioned the v slave is v specific and the fittings are also specific. I'll see if I can get hime to send me a pic.

02-25-07, 06:50 PM
i have the sammmeeeee problem and i have a stock 04 clutch..... i got to bring it to the dealer

how do you bleed it?

02-25-07, 07:18 PM
i have the sammmeeeee problem and i have a stock 04 clutch..... i got to bring it to the dealer

how do you bleed it?

Separate the trans from the bellhousing. Stick your hand inside there and put a 8mm wrench on the bleeder tube, then proceed to bleed with the same procedure as bleeding brakes. You'll need a friend to pump the pedal and keep the res. full. Good fun!!

02-25-07, 08:02 PM
According to the fellas on several Z06 forums, you can't let the clutch fluid get black. You can bleed it from the bottom after removing the trans without an adapter but some even install an external bleed adapter to make it easier. Or, as others on those forums have suggested, turkey baster the fluid from the reservior in increments to keep the reservoir fluid clear. The only thing I noticed is my Z06 clutch reservior, altho not big, is still somewhat bigger than the V's, which holds about a shot glass full of fluid. You have to keep the fluid clean or the clutch pedal will stick. :tisk:

02-26-07, 05:45 AM
I agree with most of the analysis here... I don't think your have a mechanical problemw with your pressure plate. I think its a hydraulic issue.

As far as a beefier clutch setup, it seems a little moot to invest that kind of money unless your going to be making some serious power. 400hp simply doesn't warrant beefing up, to your point the heavier rotational mass will just suck more power out of your motor and slow you down.

There are probably some nice aftermarket aluminum flywheel setups out there though...