I have sch 80 threaded PVC going into the top (output) of the booster pump. This is where it's leaking. The install is 10 or 15 years old. I cut the PVC, unscrewed it, cleaned away the old plumber's tape and inspected for cracks or nicks in the thread. I also cleaned the female threads on the volute output as best I could. I re-taped with plumber's tape and connected. Still leaks. Not sure what to try next.