We just replaced our Polaris BOOSTER Pump, but not the Volute ... (for the pool cleaner).. At the bottom of the Volute is a cheap plastic Drain Plug (ugh). It drips ! We bought a replacement plug and it ALSO drips !

Should we be putting some "tape" over the threads? Caulking? WHY on earth should this leak? (cheap **** ... rant over). Should we have just replaced the Volute at the same time?

Thanks in advance.