PoolDoc thanks so much for your help. Thanks also for combining the post about the screw with this one.

I reassembled the pump housing and motor with a new diffuser gasket and housing gasket. I filled the reservoir with water and just watched it. Sure enough, slowly water started to come out from under the pump housing. Whether it is the crack in the pump housing or a failed mechanical seal there is definitely a leak in this pump. I am going to take your advice and replace the pump entirely.

The most I can make of what's left of the model# is SP XXX5-7-1-M. At least that's what I think it says. I realize this means it should be the 3/4 HP model, but the store we bought it from recommends the 1.5HP for this pool and my mother insists we bought the 1.5HP model.

PoolDoc, do you have any links that explain how to calculate feet of head?