randomus

I had my 2008 C6 at Chuckwalla raceway last weekend and right after the second session my clutch pedal went to the floor and when I pulled it up it was floppy and wouldn't disengage. Taking it apart we found that the slave cylinder is melted and the throwout bearing is in a hundred pieces with most of them scattered throughout the clutch.

Does anyone have any ideas for me?

Here's the facts

Ambient temps were around 75-80 degrees, this was in the morning.
Slave and clutch were replaced very recently (~2 months, 2 track days, 30 autox runs).
This is the second slave cylinder in 5 months.
LS9 Clutch and slave
418 LS3 producing 511 rwhp 505 tq
Stock clutch master and lines
Thick remote bleeder for clutch (not Katech type)
Hinson urethane motor mounts (standard size)

Here's some pictures including a worn bleeder that looks like it rubbed against the body





Looks like I need to replace at least the slave and clutch, any ideas on what I need to do to keep this from happening again would be greatly appreciated.

randomus

I've also seen this thread:

http://forums.corvetteforum.com/c6-t...e-bleeder.html

It looks like the line got pretty hot from the rubbing, the plastic is pulled away. Could this have heated the slave and throwout enough to cause the failure?

Is it going to be enough to replace the stock slave and use the Katech bleeder?

froggy47

Han Solo

Probably not relevant to your failure but my old C5 Z06 had the pilot bearing fail and break the collar off that the throw out bearing rode on. When I went back I used a bushing in place of the pilot bearing. In a former life I repaired cars for a living and I saw a lot of pilot bearings fail but never seen a problem with a pilot bushing.

Nate B

I'm responding from your post on the katech bleeder thread. It looks like you're having 2 issues. The first would be the bleeder is contacting the bottom of the car causing the rub marks but that would only cause the bleeder to loosen and break. If that happens you would loose the pedal due to lack of fluid. The second issue looks like the slave is actually failing. Brian at reckart performance had seen a few of these fail including one on my car after a few hundred miles. After talking to katech they recommend the tilton race slave for cars are driven hard. Its not cheap but it works and it will pay its self off in labor from removing the trans to keep replacing the ls9 slave when it breaks again. I've had the tilton race slave and master in my car for a few thousand miles now with no issues. No more pedal dropping on hard acceleration, it never gets soft, no more fluid contamination or exploded bearings.

This is the thread on my car
http://forums.corvetteforum.com/c6-z...tick-ls9x.html

Good luck!

z06801

I had this same issue with a ls9 clutch, plastic on throw out bearing melts comes apart and ruins the slave