T-56SLPSS

About 2 months ago i noticed when i was doing a burnout from 1st to 2nd my clutch would go spongy and i would have to pump it back up. It only does it when im doing 1st to 2nd hard burnouts. Running at the track i notice alittle slipping with hard launches. I was told with long tube headers your hydrolics will heat up making it difficult to shift at high rpms so i put a high heat hose over my line. I think i need to bleed my system but after checking it out i cant figure out how to do so. I was also wondering if the drill mod may help or if you think i just need a new clutch. What do you think?