Trying to stop a very slow leak; newly installed sink.

areyourik · Dec 29, 2016

Hello,

New to the forum, and also a new homeowner, so I'm very happy to find a source of plumbing guidance here.

I've just installed a new vanity/sink. Attached picture shows my work. After install, I had two very slow leaks, one from threads under rubber gasket on drain just below sink opening, the other from where elbow meets trap. After some elbow grease, I think I've got the first under control, but still getting a very slight leak by the wall connection.

Does anything look wrong with trap configuration? Do I need a length of straight pipe between trap and elbow piece? Also, I didn't put a plastic beveled washer between elbow and threading on end of trap, but could that be the issue? Thanks for any advice out there!

Mr_David · Dec 29, 2016

what is sticking out of the wall?
A leftover piece of the old tubular brass trap arm or is there a threaded fitting that the new trap arm is pushed inside the wall fitting.

If you used what is in my 1st photo that is a typical DIY fix.
I fix a lot of those, but Not in a way DIY'r would or could fix it.

Probably not something you want to do but here's a link to how I do it.

Maybe just slap some Teflon paste on the leaking joint might help.

I use Teflon paste on the threads of the pop-up where the rubber washer sits.
Water seems to wind its way down through the thread grove.

SHR · Dec 29, 2016

Your slip joint washer is in backwards, thus the leak at the elbow.

areyourik · Dec 30, 2016

New threaded PVC fitting coming out of wall. After initial job was complete, I had a slip washer between bottom of elbow and end of trap as shown in your picture. That was leaking quite a bit, so then I removed slip washer and tightened threaded end of trap to end of elbow. Seems like I've got the leak stopped with no drips in the last day, but will try teflon tape if it comes back.

Is the slip joint actually needed when the bottom edge of PVC elbow is already beveled and attaching directly to threaded end?

Thanks for your replies and advice!

dschae1 · Dec 30, 2016

I used a string of plumbers putty on the joint between the p-trap and the elbow. I did 5 sinks recently. Two of them leaked slightly, and the putty resolved it. The putty closes up any gaps. Pinch off some and roll it between your palms to make a string.

SHR · Dec 31, 2016

Never use a slip-joint washer on the beveled end of a wall tube, leaks will result. So, good job removing the excess slip-joint washer. Never use plumber's putty on plastic material, it will eat at the plastic and cause failure of the parts.