Clutch problems

[firebird400]

I bought a 2005 GTO and the the clutch seems to loose the return in the pedal after hard acceleration or high RPM driving. If I take it through the gears without power shifting it feels like the pedal just falls to the floor; it will then grab almost immediately off the floor for an up shift or a downshift. There is no slippage and after a shift or two during normal driving the pedal returns to normal. I know that there was a similar problem with the 2005 Corvette. SSR, and CTS-V. Any help or advise is much appreciated.
My clutch also feels very stiff; much stiffer than my 68 Firebird 400 with a performance street clutch. Is this normal for a 13,000 mile car?

[ls1fan74]

Could this be a sign of air in the lines? maybe a throwout bearing but idk your car has low low miles, maybe it was beaten on before? How many miles you get it with?

[6.0LiterImportEater]

This is a very common occurence. Check out the tech page under transmisions (manual). There is a sticky in there with good info about this problem and all the fixes out there for it.

Good luck.