Kitchen sink leak--help a beginner fix it?

[canadave]

So my wife and I discovered our kitchen sink was spilling water out underneath all over the place. I had a look and discovered the issue. Essentially, the plastic nut that I gather is a "slip joint", which is attached to the piece of plastic pipe coming up from the P-trap, was no longer tightly gripping the tailpipe coming down from the sink drain. In other words, that P-trap plastic pipe was sliding (almost freely) down and off the tailpipe.

What I don't understand is--how is it supposed to actually attach, without any glue or anything like that? The tailpipe inserts downward a couple of inches deep into the P-trap pipe; if I tighten the slip joint nut at the spot where the end of the P-trap pipe overlaps the tailpipe, is it supposed to be somehow compressing the plastic slip joint washer so that it tightly grips the tailpipe? If so, that's not what's happening; even if I tighten the slip joint nut, I can grab the P-trap pipe and easily slide it downward and off the tailpipe.

Do I just need to replace the slip joint nut and beveled washer? If so, does the new washer need to look exactly the same as the existing one, or can I use one that looks different (uses a rubber instead of nylon material, for instance) as long as the diameter (1 1/2") is the same?

 

[Terry]

There are quite a few different slip joint washers out there. They're all compatible.

 

[Sponsor]

 

[WorthFlorida]

You'll usually only find them in polyethylene but they are rubber made ones out there. Lowes may have it in stock.

One of two things might have happened, the slip nut was never on tight enough and it worked lose from vibrations from a garbage disposal, or it was over tighten at one time and the slip nut cracked. The bevelled washer is compressed against the pipe and into the fitting to grab it and seal it as the slip nut is tightened.

 

[canadave]

One of two things might have happened, the slip nut was never on tight enough and it worked lose from vibrations from a garbage disposal, or it was over tighten at one time and the slip nut cracked.

That's what's so weird to me....there's no garbage disposal, and the parts (the pipes, nut, and washer) all look perfectly fine and intact. Yet the P-trap pipe doesn't tighten onto the tailpipe when I tighten the slip joint nut.

So I guess the solution is to replace the nut and washer anyway...? Can I use a chrome or brass nut instead of a plastic nut, even though everything else is plastic? Or should I only use a plastic nut?

 

[hj]

Is the slip washer installed with the bevel AWAY from the slip nut?

 

[Tuttles Revenge]

Clean the surfaces of grease too.. any greasiness reduces the chance of that slip washer from gripping well.

 

[canadave]

Is the slip washer installed with the bevel AWAY from the slip nut?

Yes.

 

[canadave]

Clean the surfaces of grease too.. any greasiness reduces the chance of that slip washer from gripping well.

Hmmm...good point. I'll have a look.

 

[canadave]

Sorry for the delay in reporting back. So, I got a new slip joint nut and washer, and cleaned the pipe connections and threads to make sure there's no grease. I was able to get the new slip joint to connect tightly, but only after really, really reefing on the nut to get it extra tight. When I simply hand-tightened it to what I would consider a "normal tight fit", I was still able to pull the P-trap down off the tailpipe with only a moderate pull. So I had to basically give all my oomph into tightening the nut with my hands to get it tightened. Now I'm worried that over time it'll come loose relatively easily, which is likely what happened to make it leak this time.

Are slip joints like this really supposed to need to be tightened to within an inch of their lives? I would've thought something like this, which is a key part of keeping the sink from leaking, wouldn't require such tightness.

 

[canadave]

So, an update....

Since I replaced the slip joint under the kitchen sink in November, got it really tight, and everything worked fine...until yesterday, when we found a puddle under the sink. The slip joint failed again (apparently from the weight of water when my wife emptied the full sink). "Slip" joint indeed, that's exactly what happened...the whole thing just slipped right off the sink tailpiece. This is now the third time that's happened (the first time, a plumber came and "fixed it", but then it's now happened another two times).

I'm running out of ideas. Are there any alternatives to these types of slip joints, which would be a different way to connect the sink tailpiece to the P-trap?

 

[Reach4]

Could your tailpiece be undersized? I know that is highly unlikely, but if you have the calipers handy, it could be worth checking.

Try a different nut and washer. Maybe even try two washers.

They make all of the pieces in brass tubing and zinc nuts too. You may be able to crank those tighter. Maybe start with a new nut and washer, and go to a brass p-trap if that doesn't do it.

Remember to keep the trap arm slope at 1/4 inch per foot. A workaround would be to rig a strap to support the trap arm near the bend, and prevent the trap from dropping. An even hokier temporary workaround would be to stack wood etc just under the bend. That should not be needed, and a change in types of washers and nuts should do it for you.

 

[canadave]

Thanks...I've already tried replacing the nut/washer unfortunately.

Funny you mention the stack of wood...I've already got that as a temporary fix, except with a dishwashing tabs container The wife is not happy with it and wants a more permanent solution. This is what everything looks like right now....

https://imgur.com/a/nMz1DSC

 

[Reach4]

Ah. A glued up trap. That is not what I expected to see. Is everything to the right of the trap also glued? I suspect your glued abs is putting force trying to bring the trap, and that nut, down.

If you could put a trap adapter to the right, and use a trap like Terry showed, I suspect things would work better.

 

[WorthFlorida]

A picture would help. Is your tailpiece metal, PVC or ABS? I would change everything from the sink basket to the wall .

 

[Reach4]

A picture would help. Is your tailpiece metal, PVC or ABS? I would change everything from the sink basket to the wall .

Is there a trap adapter off to the right? Must be. Otherwise, how could you change a nut or washer?

 

[canadave]

I just had a look...everything does appear to be glued. Is that not how it's supposed to be?

https://imgur.com/a/Bfz6lsU

 

[Reach4]

That picture tells the story better.

I just had a look...everything does appear to be glued. Is that not how it's supposed to be?

I am not a plumber. The slip joint traps are usually easier to work with, but the wider picture somehow looks better than the first picture to me.

How is the slope? I would get a level to check that before making changes.

Could it be as simple as loosening the nut on the right bowl so the right side can rise, and slipping a little spacer under the pipe as it goes through the hole? I would be interested in what the situation is when both nuts on the tailpieces are loose.

 

[WorthFlorida]

Does look like the trap arm needs some support since it looks a bit too long. A strap around the pipe and screwed to the rear of the cabinet will work for you. Most undersinks are not glued for easy disassemble for cleaning or replacing. Maybe your local jurisdiction prefers glued up traps. Nothing wrong with it. By code the only required glued traps are for bathtubs and showers since they are in the ceiling below, the basement ceiling or under a concrete slab.

 

[James Henry]

Your sink strainer looks European to me, if that's the case then it's dimensions will be in millimeters and you'll never get a tight seal. I could be wrong but you might look into it.

 

[Jadnashua]

FWIW, you'll have trouble getting the nut on a slip joint tight enough with just your hands...you often need a pair of pliers (or a wrench) to get it tight enough to stay leak-free over time. Thermal size changes will back off the nut if it isn't tight enough.