ptindall

Okay, I'm back from another day at the track with another problem so it's time for another tap into the wealth of knowledge in autocross/roadrace section.

We are all well aware of the sticking pedal problem and it just hit me really hard. Right away on lap one of each of my sessions my clutch was gone and I couldn't get fourth gear. I had to slow down, work hard to get it back into third, then run the whole track in third gear. I've run this track many times before and had a half way down pedal a couple times, but nothing like this. After the session, the clutch pedal would either be on the floor, or up but hard as a brick and even when pushed, did not release the clutch. And this is after driving around for 20 minutes without shifting. After the first session, I sucked out the clutch fluid, replaced, pumped clutch pedal, replaced fluid a couple times. Then when I went out, I tried short shifting to fourth. That worked once. Second lap it was completely gone again. Thing is, after I get off track and let it cool for a very short time, it works absolutely perfect for normal street driving. And it is not driving through the clutch. It holds WOT in first and will grab very solid on a 1-2 shift. Also, my clutch fluid is perfectly clear. Is there anything else I should be doing besides changing a clutch that isn't really wore out?

sothpaw2

I have been fighting a similar issue with mine. Be sure to use Motul or other very high temp fluid in the clutch. Changing the reservoir 3 times is not enough; I change then drive w/ a little shifting (not high rpm) then change again.

I think what we have is a bad slave cylinder. But I think to get that out you almost take the clutch out anyway. So I'm putting off this expense.

Independent1

How old is the slave cylinder in your car? They are not very well made and I would think the heat of HPDEs would shorten their life.

joemoia

I experienced the stuck clutch pedal syndrome after replacing a perfectly good clutch/hydraulics at 50K mi.

http://forums.corvetteforum.com/auto...-remedies.html

http://forums.corvetteforum.com/auto...dal-redux.html

In addition to replacing the clutch/hydraulics you can heatwrap the hard lines and remove the clutch pedal spring. In my case, I had a C6Z06 clutch/hydraulics installed and heatwrapped the lines, so far I haven't had any more problems.

ptindall

8 years old, just like my clutch. With 138,000 miles.


I'm using SRF in the brakes, but still just have cheap DOT 4 in the clutch. That's because since there is soo little exchange of fluid between the resevoir and the slave cylinder, I though the good stuff would never really get down there and all I would be doing is constantly sucking out and throwing away the SRF in the resevoir. Is there a bleeder I can get to under the car and actually flush out the old fluid so the SRF will actually make its way to the slave?

What does changing the slave cylinder involve? Can it be done without removing the entire drivetrain?

VetteDrmr

Unfortunately, no. The slave is a collar setup that goes around the input shaft to the torque tube, so you have to pull the TT, tranny, and diff to get to it.

I'm just thankful I haven't had to deal with this yet. I don't know if I just don't do enough DEs (autox is my primary fun-time), or if I'm not pushing enough power (stock LS-1 with LTs and a tune), or what.

Sorry for the bad news, but try to have a good day anyway!

Mike

AlwaysInBoost

yes there is a bleeder extension you can buy. it attaches to the slave cylinder and will allow you to suck the old fluid out with a mity-vac in a matter of minutes. I have one installed in my Z06, its made by LAPD but I wouldn't recommend that brand to you because the fitting at the end you need to suck from is poorly designed and requires special tools (aka rigging) to make it work. Hard to explain in text or even in pics but when you go to use it the first time you realize it needs something to "hold" the end so no vacuum excapes otherwise you'll be operating the pump forever with no fluid coming out.

you do have to remove the driveline to install the extention... at least all the units I've seen to. same for the slave cylinder.

I think heat warpping the hydraulics has a HUGE impact on how well the clutch pedal feels. There are guys in the drag racing section who get soft clutch pedals after only one or two passes. I have every single line in my clutch system (hydraulic or gravity feed) heat wrapped and I've never experience any type of soft clutch pedal whether it be at the drag strip, on the street or on the road course. I also run Motul RBF 600 and flush it before each event.