drove my '08 vette that I purchased last week. It had 11,900 miles on and I have driven it about 800 miles and today I backed it into my space no signs of a problem. I went out about an hour later and clutch pedal on the floor??? Googled problem and checked fluid, it was dark, I changed as the video instructed, followed directions to the "T" and my clutch is still at floor. Hand pumped the clutch at lest 100 pumps to no avail, so what's the deal??? My C5 was an automatic, so this is my first time seeing this type of issues. I am a hands on guy, can't stand to return it to a dealer and get raped with their prices. HELP PLEASE and THANKS!!!!

 

Dealer may be your friend on this one. GM extended warranty on part of the clutch system for 10 years from date of service. Check recall/tab listings for details. Believe it was for master cylinder failure but not where I can get to my paperwork on my '08. Stay tuned, someone will chime in on this and other possible causes as this has been a topic of a lot of discussion here. Good luck!!

 

As noted by the previous poster...

https://www.corvetteforum.com/forums...17-scan-1.jpeg

 

Check out the link in my signature

 

Check if any fluid is on the ground, I had this same problem and it turned out my line had ruptured from the heat of the headers.

 

thank you for the information, I will check the recalls. Thanks again

 

Yep, dirty fluid had a hard time returning to the master cylinder from the slave cylinder through the three orifice restistors in the fluid line when the assist spring was pulling the pedal back up, and is sucked the end plunger on the end of the master cylinder rod off the end of it.

So here is TXX350z link and just like his master cylinder, your master cylinder end plunge is no longer on the end of the rod to allow the master cylinder to build up any pressure.
https://www.corvetteforum.com/forums...-pressure.html
Attachment 48341327


As for the new replacement upgraded master cylinder that GM will install to resolve the problem, the end plunger is secured on the end of the rod better to prevent it from being sucked off, but is does not solve the dirty fluid problem in the first place.

so, the master cylinder has been upgraded by GM for free (will have a black tank to it, not a clear tank you have now, and the top will be labled Dot 4, to make sure that they have upgraded it correctly) still need to do the ranger method to keep the fluid clean.

Hence the plunger problem is resolve, but since the new master cylinder still has plastic internal walls, clutch dust in the fluid will score the new cylinder walls just as fast as the old cylinder walls to take the master cylinder out that way instead.

Hence GM will replace the master cylinder if the end plunger gets suck off for free (pedal dead to the floor), but if the cylinder walls are worn instead from scoring since the fluid was not changed every two years as stated in the service manual to keep clutch dust out of the system (or ranger method that you can prove with receipts to so that the fluid was being change out more frequently instead), then they will not replace the master cylinder for free instead.

 

When I bought my 08 from the dealer in November, one of the things they did before i picked up the car is replace the clutch master cyl and slave! I did not realize it was a recall!!!

 

It is NOT a recall!! It's an extension of the warranty(up to 10 years/100,000 miles) for replacement of clutch Master and Slave Cylinder, IF necessary, IF owner experiences a problem. Recalls are when manufacturer notifies all affected car owners to return cars to dealer for necessary repair/replace/fix of problem.

 

My bad!! they replaced them anyway since the car had been driven less than 200 miles a year! preventative maint work i guess!!