Before you start cutting out PVC to fix that leak try this...
For a leak at a joint on the pressure side near the pump, run the pump and have some "marine epoxy" mixed and ready, then wait for the leak.
Shut off the pump and quickly dry where the leak is. Apply the epoxy immediately.
Once the pump is off, the water in the fiter is no longer pressurized wants to fall out, but atmospheric pressure needs to get in for that to happen. This results in a suction situation were the leak is. The atmosphere will "push" the epoxy into the gap where it was leaking. It may take 2 applications.
Let it set for a day before starting pump.
This works like magic, and has fixed leaks that otherwise would have been a major undertaking. Mainly due to access issues.
Look for LOCTITE marine epoxy, widely available. Slathering PVC glue on the joint can also work.