the little cap on the top hat of the supercharger needs to be removed and filled at that point as it is the highest point. Turn the fitting straight up to fill and return it to the left after it is filled. You should consider getting the reservoir kit from LPE which uses a rotofab unit and holds about a gallon of extra fluid. That way the IC circuit purges itself once it is filled. Approx $200.
http://www.lingenfelter.com/mm5/merc...5#.UTyN-Yy9KSM