New Moen Faucets - Leaking Drain

I just installed two new Moen bath faucets. The faucet went in fine and the supply lines were a snap - no leaks. But, both drains leak like sieves. I am confident I followed the instructions that came with the faucets, but there were only pictures - no written instructions.

I used plumbers putty under the drain seat, and then under the sink came the bottom gasket, mounting washer, and mounting nut. I presume the mounting nut is to be hand tightened only because it is plastic with wings and not flats for a wrench. Then a seal and the tail were added. The sink does not leak between the sink and the bottom gasket. The water is coming down the threaded portion of the drain seat (upper pipe?) below the mounting nut. It's dry above the nut.

Should I pack the inside of the mounting nut with plumbers putty before tightening it?

Suggestions?

This was supposed to be a quick Saturday project! And it needs to be because our other bathroom is under construction.

Thanks,
Bruce

I believe I'm reading your post correctly in assuming that it is leaking at the threaded tailpiece. A small amount of teflon pipe dope (thread seal) on the threads usually works for me. Give it a try.

If the leak is coming from the popup rod, try taking the rod out and putting a small amount of pipe dope on the ball itself.

A word of caution: Check to be sure the pipe dope you're using is ok for your application. Some arent made for plastic; others are.

Good luck and hope this helps some.

Thanks

The teflon pipe dope worked.

Thanks for the help.