How to fix leaking bathroom sink drain where PVC meets ABS connection

bathroomdrainleak

My bathroom sink drain began leaking recently. The PVC connection that meets the ABS connection is the culprit. See picture with red arrow below.

After taking everything apart and cleaning the parts, I discovered the ABS threads look to be dented (see picture). I suspect the leak occurs because the tapered gasket cannot form a water tight seal where it meets this dent.

How do I fix this?

  1. Can a material of some kind be added to fix the dent, but still allow the threads to work?
  2. Do I have to replace the ABS thread connection entirely? I'm not sure how to do this exactly since I believe ABS connections are cemented. Guidance is appreciated if this is my only option.
  3. Other?

It looks like there may be a glue type residue on the ABS threads. I wonder if there was once glue of some kind that broke down over time and caused the leak now. I can't imagine why this connection would have sealed without some kind of other stop gap measure in place to account for the dent.

enter image description here
enter image description here

Best Answer

Try @JACK solution of cutting off bad threads. You might also try a different style slip-joint washer (they come in plastic or rubber). Tighten the fitting, hand tight is not enough. If that doesn't work, the fitting is toast. I would cut it off and glue a new one on, then use the proper slip-joint assembly with no glue, goop, caulk, goo, or any other such nonsense that is unlikely to work.

You have a couple problems though.

  1. If you cut it off (even if you cut carefully, which you should) there will be very little pipe remaining outside of the wall. That's OK though, glue the new (1 1/2" male adapter) to whatever is left and it will be fine. Use abs glue if you get an ABS fitting, use universal or multi purpose glue if your new fitting happens to be PVC.
  2. The PVC trap arm may end up being too short after you shorten the wall pipe (it depends how much was left inserted into the wall pipe). If so, you'll need a new P-Trap.
Related Topic