Here's how the sink currently is hooked up:

Rear shut off valves: Rear shut off valves

Front hookups to sink: Front hookups

The approach I was looking at - after significant confusion at home depot (I'm honestly still a bit confused): Approach

I would disconnect the hot water input, and connect it to part A (A = one of a 3/8 in. MIP and 1/2 in. MIP Brass Water Supply Adapters Link ), connect to a tee (B Link). And then C is a hose from a universal dishwasher supply line and D is a faucet hose. Is this correct? Part A came with a brass ferrule but it was under a nut I had to remove and it doesn't seem like it would fit? I assume all threads here should receive plumber's tape? Anything I'm screwing up?

Thank you!

  • Do make sure to check if your dishwasher even supports being connected directly to a hot water line. Most dishwashers don't like this and might thank you in a less pleasant way. Commented Aug 27, 2018 at 12:28
  • Consider that you may want separate shut off valves for the faucet and dishwasher
    – mmathis
    Commented Aug 27, 2018 at 13:06

2 Answers 2


The types of fittings that you linked are compression type fittings that are meant to be used where a compression ring is placed around a smooth copper or nylon copper water delivery pipe. Your setup is using the flex braided water connection hoses and really should use the proper type fittings.

If I was addressing this connection problem I would focus on replacing the coupling nipple at this connection:

enter image description here

(Picture source from question at this posting)

Note that your sink unit flex pipe ends with a 1/2" fitting. Replace the nipple with a 1/2" NPT Tee fitting like this:

enter image description here

(Picture source from amazon.com)

Then adapt the branch of the Tee to fitting with a 1/2" female NPT to 3/8" MPT fitting to connect to the dishwasher supply line using a fitting that looks like this:

enter image description here

(Picture source from amazon.com)

Technically the only fitting threads that need the Teflon plumbers tape are those where the water seal is made with the threads themselves such as between the Tee branch and the 1/2" to 3/8" adapter as suggested above. The braided hose connections typically have a black or red rubber washer inside the female coupling nut that is designed to seal against the end of the mating male fitting and so no plumbers tape is really needed there. Some folks however seem to like to use the tape on all the threads such as where the nipple was installed in your pictures between the two flexible lines.

  • Thank you very much for the reply! Surprisingly and unfortunately, it seems that the threaded portion is integral to the hose that goes to the sink and not a nipple? At the very least, on both supply lines, a wrench + tongue and groove pliers and the threaded portion wouldn't budge and I'm pretty sure I was on the verge of breaking or deforming the piece.
    – user982835
    Commented Aug 27, 2018 at 12:47

I agree with Michael's answer but I would change the valve to a 2 port that way there are less connections to leak. Don't over tighten those compression fittings, my son installed an ice maker and flooded under his sink. When I got there to fix it he said he tightened it as tight as he could and the leak just kept getting worse. Hand tight then a 1/2 to a full turn tighter is all that is needed two tight dammages the fittings.

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