The hot water supply hose under my sink started leaking after I replaced the popup drain on the sink. Apparently I disturbed the hose in some way. It is leaking from just above the nut where it connects to the shutoff valve. I removed it and added new plumbers tape, and after reconnecting it was still weeping after I checked it 10 minutes later (about 1 drop). So I tried tightening it more, and it began leaking faster (again, from above the nut). Do I need to replace the hose itself? I'm thinking the gasket/washer, whatever it is, is just old. I have no idea how old this hose it, at least 10 years.

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5 Answers 5


In this case, a gasket in the hose is likely degraded. Replace the entire hose with a new one. For this particular fitting, PTFE (plumbing) tape should not be used, and perhaps could be causing the leaking if it is preventing the hose from seating properly.

  • Is it possible just to replace gasket? Commented Nov 18, 2018 at 19:45

Does flexible = plastic or flexible = braided hose with permanent nut fittings on the ends?

If this is one of those braided type hoses with permanently attached fittings on each end, then they seal with a rubber gasket permanently installed in the nut fitting. The hose itself could be cracked from age or hardened enough that it doesn't engage with the barbs under the swedge collar and can leak there as well.

The hose assembly is cheap, just replace the whole thing.

Flexible plastic is another thing all together. The top has a ball surface that seals when the nut pushes it into the faucet fitting and the lower end has a nut and a compression collar. If the compression collar gets damaged, it can be replaced.

  • I knew I'd forget something! Flexible = braided hose with permanent nut fittings on the ends. I'll just replace it then, sounds like it's the best thing to do. I did not know overtightening would damage, but suspected it as soon as I did and it leaked worse. Good to know about the plumbers tape too, I also, as many probably do, assumed it was to help seal. Thanks to everyone for their great advice, I know someone will appreciate it (as I have) when they google the same problem. :) I'll go ahead and add a photo just for clarity, though I already have my answer. :) camera was in husbands car. Commented Nov 14, 2012 at 18:32

I had to replace my under sink 4 gallon hot water heater after 18 years (6 year warranty), It feeds the sink and two dishwashers, one on either side of the sink. When I was done the two flexible lines that go to the dishwashers had a small leak. Did not want to replace the lines since they were custom installed through the wall in the back and would have been a real chore to do. I thought of calling a plumber but did not want to spend the money. So I did the repair myself. I got #7 rubber "O" rings from Home Depot. Lathered them with silicone and pressed them into the end that was leaking. #7 "O" rings are a tight fit but that is what you want. Here is the tricky part. When reinstalling the line, you will need to torque the fitting down much tighter than you would normally since you will compressing the "O" ring into the area where the original rubber gasket is. Do not remove the original rubber gasket even though at this point it would not work alone. This solved my problem, saved me $40 in new hoses and untold grief removing the dishwashers and hoses and reinstalling.


Over tightening a plumbing fixture can be just as bad as under-tightening, as it can damage the threads and prevent a proper seal.

In your case, you should try to fix this first by reconnecting the pipe with a cleaned fitting:

  1. Remove the hose.
  2. Remove the existing tape completely.
  3. Clean the threads on the hose and the fitting with a wire brush.
  4. Wrap new silicon plumbers tape around the threads TWICE - no more - too much is not a good thing. This tape isn't to create a seal, it's to ease the turning of the nut.
  5. Reconnect until the hose fitting is snug. DO NOT over tighten as this promotes leaking.

If this doesn't work, disconnect the hose and replace with a new wire mesh hose, using the same taping method.

  • 1
    Perhaps this is a compression fitting where no PTFE tape should be used?
    – Pigrew
    Commented Nov 13, 2012 at 19:38
  • Good point! Most of these kinds of fittings are compression style, aren't they? Commented Nov 13, 2012 at 19:39
  • 4
    I think the flexible wire mesh hoses usually have a rubber washer for a seal; they are not compression fittings.
    – Steven
    Commented Nov 13, 2012 at 20:20
  • 1
    Compression fittings on metal tubes have a limited number of times they can be used. The secret is to tighten them just enough to seal. On next disassembly, do the same, just enough to recompress. Over-tightening them does not make them seal better and often intensifies the leak or cracks the nut. Once they start to leak, you throw the piping and nuts away and start over again. It's why the braided hoses are in vogue now. They use the same faucet and valve nipples, but the seal is a flat neoprene gasket that seals a lot easier. Commented Nov 13, 2012 at 23:49

I prefer to use the braided hoses over PVC (Never had a rupture). Their problem area is usually the connection to the shut off valve. I have had new hoses to leak due to over tightening or use of Teflon tape (unnecessary). The remedy is to replace questionable and old hoses. Next, remove unnecessary tape. Then, hand tighten with approximately 1/4 turn (or only enough to stop any leaking).

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