A/C water intake pump dripping

[Peterbreit]

I replaced my old, frozen up A/C pump with a similar KoolAir PM 1000-1 pump. Boat is a 200- Beneteau Oceanis 461.
The hose connection is leaking a steady trip of sea water. Location in the 461 is below the waterline in front of the engine underneath the starting battery and companion way stairs. Lot of stuff to remove.
The hose from the through-hull attaches to a Marlon 90 elbow which attaches to a bronze adapter (WM Bushing-Brz 1x3/4 #479678) which attaches, screws in the hard plastic pump. That's where it is leaking.
I tried first without Teflon tape then with Teflon still leaking, BUT only when the pump is not running. When it is pumping water (A/C compressor is on running) no water tripping. Question: How to best connect a metal adapter with a plastic screw in? I just hope I did not ruined the plastic threats in the pump housing. Shall I use a sealant ?
Appreciate any help.
Peter on "Belvedere"

[Outlaw7]

Change the pump to a March unit and do away with that Chinese pump.

[DeepFrz]

Use a sealant rather than the teflon tape. Plastic fittings don't need Teflon.
Installation