I recently finished my ls1/t56 swap into my 70 camaro. I drove it one night, and it ran and drove great. The next day, I went to drive the car and the clutch was slipping really bad in almost every gear. I immediately brought the car home and parked it and tried to figure out what the problem was.

I started with bleeding the clutch again. When I opened the bleeder, fluid came out of the bleeder like it was somewhat pressurized and the fluid was warm. I went up to check the master cylinder and it was about half full and when I took the cap off, it also was under some pressure. When I continued bleeding the clutch, it was normal, and just flowed out of the bleeder rather than blasting out like it was under pressure. I took the car for a drive after that and the clutch gripped really good and everything was back to normal. Any ideas on what caused that to happen? I don't want to ruin anything or have it act up again. I was thinking that I might have had the reservoir too full and when the fluid heated up, that it pressurized the whole system, and the clutch couldn't fully engage. I only had the reservoir half full and then put the rubber piece on and then the lid. Anyone have any ideas?

 

You could be right dont over fill it. Is this all stock LSx clutch componets, master slave & line?
The pedal isn't causing it is it, not returning fully etc?

 

I checked out my pedal and it wasn't fully returning, causing the throwout bearing to spin and heating up the fluid causing pressure. I fixed the problem, and all is great now