My bathroom sink got severely clogged up. I'm a structural engineer, but I have no aptitude whatsoever to DIY. This, however, I felt was within my reach, so I decided to give it a try. (Also, I'm Brazilian, so forgive any incorrect terminology)

I unscrewed the trap, removed it from under the sink and removed the snake of gunk that'd completely clogged the inlet.

My problem is in putting everything back together. This is what I have:

enter image description here

enter image description here

The only variable I'm unsure of is the rubber ring (seen around the top of the pipe on the first picture). I don't remember where it was when I removed the pipe. In the picture, it's pushing up against a lip at the end of the pipe, but it may not actually belong there.

If I place it over the pipe, trying to align the pipe, the ring and the drain before screwing everything with the nut, it leaks (I tried some three times).

If I place it where it is shown in the picture (beneath the lip), I have some trouble getting the nut past it (I have to turn the nut around and it slowly moves past the ring). Eventually I get it into position, but after I screw it onto the sink and open the tap, it leaks again (though it takes a few seconds). (I also tried this three or four times).

I've done some googling but, though I've found dozens of links and videos on replacing the strainer, this seems to be so trivial no one's bothered.

Many videos mention a gasket at the mouth of the trap, but it's always shown embedded into the nut. I'm unsure if this is a different mechanism or if this ring is that gasket which has come loose. The latter would mean my attempt with the ring where it is shown should work, but perhaps I'm missing something (should I use putty or thread seal tape around the drain?).

  • Would you provide a longer-range picture showing what the vertical metal pipe's bottom connects to? Nov 1, 2016 at 1:36
  • @DanielGriscom: Done.
    – Wasabi
    Nov 1, 2016 at 1:57
  • I think it is in the correct location but it is used. A new seal or some additional calking or sealer may help. Once a rubber seal has been in place it is best to replace I with a new one.
    – Ed Beal
    Nov 1, 2016 at 10:26

1 Answer 1


The ring goes where you have it and you're over-tightening. These things need barely more than what you can do with your hands. (There's really no pressure to contain with a sink drain.) The ring should stay inside the nut and seal the pipe to the nut. The nut seals against the bowl threads.

  • Thanks. I just tried again with less torque (using just thumb and finger to tighten), but it still leaked. I also checked and the leak is at the bottom seal, by which I mean that the water isn't flowing up the threads, but bypassing the ring. Is there an elegant way of getting the ring into its correct position or is my "spin the nut past it" the way to go? I'm just not sure if its 100% correctly positioned. I also wonder if I may have damaged the ring in my previous attempts, though there are no visible signs of damage.
    – Wasabi
    Nov 1, 2016 at 1:49
  • 1
    Damage to the ring crossed my mind, but I didn't want to insult. Again you mention spinning the nut past the ring. I'm confused by that approach. It's not something you see anywhere in industry, really. The ring should stay between the inner flange of the nut and the flange on the pipe.
    – isherwood
    Nov 1, 2016 at 13:10

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