when replacing the pump you must have seen the little standpipe with two O rings on it, that connects the oil channel in the pump plate to the rear axle housing. Another one is between the rear axle housing and the 3pt hitch cover, and you most likely blew an oil ring on either of them.
When you're at it, replacing the o ring, also check if the rolled steel pipe pressed in the cast iron rear axle housing, is undamaged.