The reason that I was believing that it's crankcase pressure is that the engine only has 150 miles on it and it's already had 6 different rear main seals (different brands, one piece, two piece, tried everything) put in and two different retainers and it still leaks. I doesn't leak right at startup; it usually runs for about a minute or two and then it starts leaking badly out of the seal to where it's almost a steady small stream of oil. I've checked all plugs on the back of the engine, valve cover gaskets and everything is dry up top. I can see it leaking right at the lowest point of the seal/ crank flange area. This I why I was thinking it was too much pressure building up; no leak at first and after a minute or so of running, too much pressure builds up and the rear main is the weak point. I'm not trying to band aid anything with the pump, I'm just willing to try anything at this point so that I can drive my car.