SuperCharger oil leaking.

Hey guys, I got a question for ya. I have a '98 Grand Prix GTP coupe. I park it on a level spot and remove the little allen wrench plug to add supercharger fluid and I fill it with the right stuff from GM up to the level of the hole and then I put the plug back in. Everything is good so far. But then I park on an incline towards the passenger side and some oil leaks out. It comes out of the little brass breather in the center of the drive pulley. Why does it do that? I've never messed with that. I have changed the fluid though. Thanks in advance.

There is a snout seal that should fix that.

http://shop.zzperformance.com/store/p/1003-EATON-Snout-Seal.aspx

rebuild instructions.

http://www.rollingperformance.com/snoutrebuild.htm

video of snout seal replacement.

http://www.youtube.com/watch?v=ICw-6MTcsBM