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StevenC 11-13-2011 07:48 PM

Sink drain leak?
After switching from a pvc to a brass drain and trying several different design washers I can't get the rubber mack washer to completely seal against the sink bottom. Water slowly begins dripping between the two. Could the bottom of the sink be uneven from the factory to prevent a flush seal? Btw I've cranked on the nut with no luck.

Any advice is much appreciated, thanks.

Redwood 11-13-2011 08:11 PM

Coat the threads on the drain where the mack washer lands with Teflon Paste Pipe Dope. The water is leaking down the threads under the washer.

joecaption 11-14-2011 05:10 AM

Remove the drain, take some plumbers putty and roll it between your two hands until you have what looks like a 3/8 dim. X 5" long piece. Wrap it around the bottom of the drain where it hits the sink. Tighten the nut and wipe off the excess.
Tape on the threads will do no good.

Redwood 11-14-2011 07:50 AM

No need for the putty there, the rubber washer will seal fine against the sink.

The problem is the rubber washer isn't sealing the threads so that is where the leak is coming from. Water is seeping down through the threads.

Do not use Teflon Tape! But do apply Teflon Paste such as Rectorseal T+2, Megaloc, or other brand, to the threads that will be running inside the Mack washer when tightened...

This will cure your leak... Guaranteed!

joecaption 11-14-2011 08:51 AM

I've installed 3, new faucets this week and not one came with a rubber washer for inside the sink. Just the thick one for under the sink and a thin plastic one so as the nut is turn it slips instead of turning the washer as your tightening. It would leave the trim ring up to high off the basin.
Hopfully the poster will get back to us and tell us what worked for them.

Redwood 11-14-2011 10:22 AM

Putty is for inside the sink between the drain flange and the sink basin. The worst case scenario there is water will leak down the drain instead of staying in the basin when the stopper is in place.

This leak is under the sink with water coming down the threads between the drain and the mack washer.

StevenC 11-14-2011 04:25 PM

Thanks for all the replies guys! I have plumbers putty rolled under the drain flange and sink basin already. I wasn't able to tackle the job yet as I've picked up a stomach virus.
Redwood, so your saying its leaking down the threads? Will pipe dope be sufficient on the threads?

Redwood 11-14-2011 11:13 PM

Yes and yes...

but the Teflon dope needs to be on the threads up inside the mack washer...

StevenC 11-15-2011 07:52 PM

Ok thanks!

Also, the brass drain and the P trap don't line up, they're about 3/4" off (in every direction) because I'm using a standard P trap with a short sink.

Right now I'm using the plastic flex drain 1-1/2" but it doesn't seal properly. What other options do I have?

joecaption 11-16-2011 03:59 AM

Post a picture of what you have and we can come up with something.
If the old one did not leak, why did you change it?
If you still have the old one take a look at it and see how it's differant then the one you bought.

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