Home>Discussions>PLUMBING>Dishwasher / compression fitting.
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JCphotog
Dishwasher / compression fitting.

A few weeks ago, I installed a dishwasher, and used a floodsafe braided steel water supply hose from home depot. Hand tightened + 1/4 turn on both ends. The dishwasher side is dry, the fitting attached to the supply leaks. I bought a new hose, re-attached it, same story. I tightened a bit more than 1/4 turn close to 1/2 turn, and it still leaks just a but. a drip every 5 to 10 seconds or so.. Any advice. I didn't want to over tighten.

The shut off valve on the supply is brand new, so the threads look really clean and nice...

havanagranite
Re: Dishwasher / compression fitting.

did you first wrap the threads with teflon tape?

JCphotog
Re: Dishwasher / compression fitting.

I've been told not to wrap threads with teflon tape in a compression fitting.
When the tape gets in the way, it can cause an un-even seal..

This fitting has a rubber gasket.. so I'd think that teflon tape wouldn't be needed...

Update: tried it for the heck of it, it made things worse.. so I cleaned the threads, removed the tape, and re-mounted. Still leaks very slowly...

Mastercarpentry
Re: Dishwasher / compression fitting.

You're right about not using teflon here. What you're probably experiencing is a maximum-sized male(supply)thread and a minimum sized female(supply tube)thread. While you don't want to overtighten needlessly, if the supply fitting is in good shape the gasket isn't being compressed enough which brings the leak. Go back and tighten it some more being sure to hold the valve side firmly so as to not let it move at all. The worst that should happen here is having the outer supply tube fitting split if it simply can't take it. In that case try another supply tube.

With the current spate of imported items, you run into improper thread fit more than ever before and it's not necessarily because they're selling cheap stuff. We're making measurements on the "Inch" system and they're making them on the Metric system, so when the tolerance range is considered they convert these measurements to the nearest metric equivalent. Most of the time it's close enough but sometimes you get what you've got, a poor fit and problems.

Just another example of why we should convert to metric!

MC

JCphotog
Re: Dishwasher / compression fitting.

Yeah. I hear that. The tough thing here, Is the leak appears to come from the braded hose "female" to the supply / shut off around the threads, that said, My neighbor just suggested taking some dry toilet paper and holding it next the fitting above which goes to the sink, it's possible that it just appears to come from the braided hose connection.

Another friend said he had a similar issue, and connected the braided hose to threaded copper on one end, then did a regular compression fitting to the supply...

havanagranite
Re: Dishwasher / compression fitting.

http://www.thisoldhouse.com/toh/article/0,,202345-3,00.html

click on this article and please read simple on how to eliminate leaks.

JCphotog
Re: Dishwasher / compression fitting.

It's a great article. I read it before installing, which is why I went with the steel braided line, even one with the anti flood shut off... I didn't over tighten. Went to 1/4 turn. Then I tried 1/2 turn. No go. Went further, it leaked more. I bought a new hose.. Still leaks. We're not talking a huge flow, just an occasional drip, and the pan I placed below feels wet the next day..

I know it's not the shut off, since when I shut the water, there's no leak..
So if I'm missing something please let me know. Worst case a few folks have suggested rubbing a bit of pipe dope on the threads..

havanagranite
Re: Dishwasher / compression fitting.

a direct quote from that article

Schlott recommends giving the elbow a couple of extra wraps of Teflon tape before inserting it (four wraps in all). Wrap the tape firmly in a clockwise direction.

canuk
Re: Dishwasher / compression fitting.
Quote:

We're making measurements on the "Inch" system and they're making them on the Metric system, so when the tolerance range is considered they convert these measurements to the nearest metric equivalent. Most of the time it's close enough but sometimes you get what you've got, a poor fit and problems.

Eh? I don't totally agree with that thought.

If it's a 3/8 " pipe fitting then it will be made to the appropriate 3/8 " size with the correct pitch and number of threads spec'd for that fitting. It may be more of poor overall quality manufacture.... with same being for anything in metric size.

djohns
Re: Dishwasher / compression fitting.

I've noticed that a lot of plumbing fittings are being made in
China . Think about that for a minute . ;)

kcb
Re: Dishwasher / compression fitting.
Mastercarpentry wrote:

Just another example of why we should convert to metric!
MC

Or better yet, but American.

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