Disposal: Leak above Metal Slip Nut to PVC Union (w/ photo)

[Zmonet]

The garbage disposal was put in about three years ago but today I noticed water leaking out onto the floor today. On examination and testing, the leak comes from the union of the metal slip nut, black PVC from the garbage disposal, and the white PVC pipe for the trap (see picture). The leak comes at the top of the metal slip valve, not on the threads. This would seem to indicate to me that the threads are sealing fine but that water is backing up and going through the top of the metal slip nut.

I've undone the slip valve, cleaned the pvc and retightened, as well as trying different levels of tightness but it always gives me a leak as soon as the water is flowing for 20 seconds or so (maybe backing up a little in the trap?) The only thing connecting the two is the slip valve and the pvc -- there is no sealant or washer. Anyone have any suggestions? Am I missing a gasket? Thanks!

 

[MACPLUMB]

Yes you are missing a washer that goes under the nut and seals where it leaks

 

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[Zmonet]

Thanks for the info! Can I get a rubber washer at most hardware stores? I would assume this one would be 1 1/2". Or should I buy a new slip nut assembly? Thanks again for the help.

 

[MACPLUMB]

YES A NYLON WASHER AT ANY HARDWARE STORE

 

[Zmonet]

I removed the slip valve and found that there was a nylon washer already in place. Regardless, I had bought a new one, so I replaced it and tightened everything up. It unfortunately still is leaking from the same spot. Should I replace the slip not? What else should I be looking for? I've looked for possible leaks coming from the disposal and dripping down, but that is not the case.

Thanks for any help!

 

[Dj2]

The washer has a cone shape. make sure the narrower end goes first.

Also, switch to a non metal nut.

If you still have a leak, it's time to remove the drain from the GD to the wall and install new parts. Stay with one type (e.g all PVC).

 

[Reach4]

Your photo is not sharp enough. Your slip nut (chrome in your photo) needs to be screwed onto the mating thread. Is that a green washer visible under your slip nut? The washer should not be visible.

 

[Jadnashua]

When you tighten that nut, it wedges the tapered sealing washer against both the tubing inserted through it and against the inside of the fitting, creating the seal. The outside of the tubing going in needs to be smooth as well as the inside of the fitting to make that seal and it can't be skewed much from being straight into the fitting. If the washer is damaged, or inserted the wrong way, it won't work. If that tubing that gets inserted into the fitting is too short, it could leak. Generally, it's hard to tighten that enough by hand to make the seal...you need a wrench or a pair of pliers.

I've found that some of the low quality nuts/fittings, you can't tighten the nut properly since it barely engages the threads and once enough pressure is applied, it pops back up a thread, loosening it some, never achieving the pressure it needs to seal properly.