Replaced spa pump, leaking water from one corner

[pcm2a]

Replaced a century spa pump in a super pump 2600. On one side at the bottom corner I have a leak. When I pull the motor back out what should I be looking for? During the replacement I used a go kit to replace all of the seals/gaskets. There was one that was not present when I removed the pump and it seemed too big to use anywhere. I assume it's not the problem since it was there when I pulled out the old one.

Go kit:


Housing gasket?


Leaking from here:

 

[pcm2a]

This has to be the problem: Genuine Hayward Seal Plate Gasket For Superpump. SPX1600T is a round gasket that fits into the pump body, to seal up to the Seal Plate. I never looked at the pool housing to see if there was some groove.

I should have noted that it only leaks when the spa pump is on. The pool pump pumps water through the spa pump and it does not leak. Spa pump acts as a booster when in spa mode.

Update: Easy breezy replaced that housing gasket seal. Leaks even worse now.