Help with Bathroom Sink Drain Leak

[Norm K]

We're selling our home and the inspectors discovered a leak in one of the bathroom sink drains. I figured I'd find a junction at the trap that would be easily addressed. Unfortunately, that's not the case.

The leak is coming from the joint where the black stub connects to the fitting (white) that protrudes from the wall. It leaks quite a bit from about the seven o'clock position. The joint appears to be threaded but I'm not 100% certain of that. I tried twisting it by hand, but it didn't budge. I wasn't inclined to put a pipe wrench on it before asking for help here, for fear of tweaking something behind the wall, and creating a real mess.

Is this likely a threaded joint and, if so, if it was properly installed should I be able to remove it with a pipe wrench and re-seal it?

I'm inherently cheap so I really don't want to call a plumber, but I also don't want to either make a bigger problem out of what should be a relatively small one.

PPOT Brain Trust advice appreciated.

[masraum]

I'm no expert, but I think the white collar is threaded, not the black extension. I believe you unscrew the collar and then the black part will pull straight out. Then you can probably install a new collar and ferule or replace the black part and the associated parts.

[URY914]

Flexseal and be done.

[Norm K]

Originally Posted by URY914

Flexseal and be done.

Don't think that hasn't come to mind, but I want to make sure it's done right.

I put a pipe wrench on it after reading masraum's reply, and pulled fairly hard. It didn't budge, and I'm not sure how hard one can tweak on PVC before creating problems behind the wall.

_

[masraum]

Originally Posted by Norm K

Don't think that hasn't come to mind, but I want to make sure it's done right.

I put a pipe wrench on it after reading masraum's reply, and pulled fairly hard. It didn't budge, and I'm not sure how hard one can tweak on PVC before creating problems behind the wall.

_

That sort of thing concerns me as well when working with plumbing whether it's PVC or copper or whatever. Good luck!

[Crowbob]

Before you go all medieval with a wrench, make sure that joint isn’t glued together. It very well could be going by the pic.

[masraum]

Originally Posted by Crowbob

Before you go all medieval with a wrench, make sure that joint isn’t glued together. It very well could be going by the pic.

It probably leaked before and got flexsealed by the PO.

[Norm K]

Originally Posted by Crowbob

Before you go all medieval with a wrench, make sure that joint isn’t glued together. It very well could be going by the pic.

That's my concern, Cb, which is why I'm not sure how to proceed. It's leaking at about the seven o'clock position, right where black meets white in the image.

I don't see a way to remove the offending area, as there's no room to work, short of removing the vanity and cutting the wall away. I'm now wondering if there's a way to sleeve that section with a smaller OD pipe that extends far enough beyond the leak (to a few inches behind the wall) that, with some sealant between the OD of the new pipe and ID of the existing pipe, will solve the issue.

That assumes, of course, that I could then piece together the other fitting and joints to accommodate the new stub-out size.

I can successfully rebuild the engine of my 930 in my basement but I can't figure out how to repair this sort of leak.

Plumbing sucks!

_

[techman1]

Norm,
if you clean off the gunk on the collar, is it smooth, or are there ridges to facilitate grabbing it?
If ridges, I would guess it is threaded.....

[gregpark]

I'm no plumber but I think the black is abs and the white pvc. Two different glues required. I would think it's a tapered compression ring that needs replacing. I see that the other end of the black pipe is free so I'd put a pipe wrench on it, some channel locks on the white collar and give it a go. No stress on the behind the wall plumbing that way

[Norm K]

Could have it been this simple?

I received a copy of the inspection report and read where the inspector noted that he'd tested each connection to see if they were tight. I wondered if in doing so he might have pulled the sleeve out a bit when he was testing the other joints, and not noticed what he'd done.

I loosened all the connections, pushed the sleeve in as far as it would go (2-3 inches farther in then I'd found it) and re-tightened everything. I then ran the faucet on full-blast - no leaks. Filled the bowl, then drained it while the water was on. Still no leaks - or should I say "spray" because that's what it was doing before, which is why I was curious about the timing of the leak, as we've never noticed a thing: no drips, no staining, no wet hand towels or wash cloths, nothing ... until after the inspection. And as fast as the water was coming out, there would have been no missing it.

Anyway, did I get lucky or did pushing the smaller OD pipe farther into the larger one simply hide a problem that will return?

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[rusnak]

It could very well be a bad repair that has failed. Hard to tell in that picture.

I would probably cut the black pipe at 4" or so and take a look in there to see what's going on. But be prepared to remove the back wall of the cabinet and have to cut into the wall to get it repaired right.

[Bill Douglas]

Sometimes with those pressure fittings the rubber seal gets misaligned or twisted. I'd be inclined to undo it and see what's happened and probably clean the area and replace the rubber seal - if that's the problem.

[rusnak]

Damn lucky if it is. Yeah, some pipe compound would be called for on the rubber donut.

[Amail]

Is there any water damage underneath the leak?

[masraum]

I suspect you've fixed the problem with your moving and tightening.

[dad911]

Looks like someone tried to glue an ABS pipe into a PVC fitting.

The right way is to remove the black abs piece and rebuild it like post #2

[IS300]

if you get them apart need to get the special glue abs to pvc

Do not put a wrench on it!

wiggle it loose

[plumb4u2]

Norm K
What you have there is ABS (black pipe) glued into a PVC fitting in the wall. PVC and abs can not and are not allowed to be glued together by code, they can only be connected with a rubber fernco coupling
They do make a “all purpose glue” but by code we’re not allowed to use it

Read your inspection report you may still be required to have a licensed Plumber check it out

[Superman]

It is not leaking now. Return to your original plan and sell the house. Before it leaks again.

That said, it sounds to me as though you fixed it. It sounds like it only leaked briefly, perhaps because the inspector messed with it.