There is a possibility that the new pumps goosed, my mate got a ****part one for his 200 90 and he might aswell not have bothered for the good it did. Check the banjo fitting on the pump, there's a small rubber seal that fits to the banjo that goes inside the pump which if not fitted spot on travels down the banjo and creates a "seal" around the hole in the banjo preventing oil passing through. But if the pump squeels that normally indicates either the belt slipping or worn pump bearings. Is there any chance you have got the pipes crossed over somehow? Also check the belt tension again.