Dishwasher hookup leak

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Just got a new dishwasher (Kenmore model 665.13834) and I'm having trouble with the water hookup. I bought the required elbow that goes between the water supply line and the water inlet valve. I just CANNOT get it to not leak. I think I've finally gotten it to stop dripping from the supply-side of the joint with the use of some teflon tape, but I can't seem to stop the leak from the valve side.
Here's a picture of the assembly (the dishwasher is turned on its side to expose the bottom):
http://home.comcast.net/~esionder/temp/dishwasher1.jpg
I've tried two different elbows. I've tried it with and without teflon pipe tape. I've run out of ideas. Does anyone have any other tricks for making water-tight connections in this kind of situation?
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Nil wrote: ...

Doesn't appear the elbow is screwed into the fitting very far -- what are you using for a wrench and how much are you tightening the fitting?
Should tighten right up.
How many wraps of teflon? I'm old fashioned but I still like plumbers dope although the teflon should do the trick.
Only reason otherwise would perhaps be oversized or poorly cut threads on the valve; I've seen quite a lot of Chinese fittings w/ very poor tolerances. If you're tightening w/ (say) 10" wrench and putting a good pull and have 5-6 wraps of teflon and it still doesn't hold, ask for a replacement valve assembly.
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You're right, it's not in very far, maybe 1/3 or 1/2 the way. But that's as far in as it goes, and it's about as tight as I dare.

I've tried it several times with 1 - 3 wraps. I think it's got about two on it right now.

Maybe I'll try a few more wraps of teflon. Then maybe I'll take the valve to the hardware store and see if I fan find yet another elbow that fits better. If all else fails I'll call Sears, but based on a recent experience, finding someone there who knows what they're talking about and is willing to help me by swapping a part is an unlikely scenario.
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First, take a look inside the female threaded end on the flex water line. I'll bet that there is a rubber gasket in there. If so, you should *not* use Teflon tape on that connection. The rubber seals between the end of the water line and the elbow, while the nut simply holds the joint together under pressure. You don't need Teflon tape between the nut and the elbow, since water shouldn't ever reach the nut. (But using Teflon tape can make it difficult to tighten the nut enough, leaving the rubber gasket uncompressed, and allowing water to leak between the hose and the nut).
On the other hand, the elbow to water valve connection is metal to metal, and should have Teflon tape. It doesn't look like you've screwed the elbow in very tight. You should tighten hand tight and then another turn or two with a wrench. When you're done, half or more of the width of the original Teflon tape is usually hidden inside the connection. In the photo, assuming normal half-inch wide tape, it looks like almost the entire width of the tape is still outside the joint.
    Dave
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On 28 Jul 2008, snipped-for-privacy@cs.ubc.ca (Dave Martindale) wrote in alt.home.repair:

I tried it without the teflon, and it was leaking. I understand that it shouldn't be necessary, but I was careful to not cover the tip of the tube where the rubber gasket would hit. It seems to be watertight, so I'll leave it alone.
It's possible that the leak was from the valve side all along. It was hard to see what was happening when the unit was in its upright position.

It's already screwed in quite tight, maybe 3/4 to not-quite-one full turn after finger tightening. I was afraid the brass might crack if I tightened it more. Is that a valid concern? Or can brass stand that kind of stress?
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Nil wrote: ...

Unless it's terribly _tight_ as opposed to loose tolerances, 1 turn after fingers can't be very tight at all...how much actual torque are you applying is the key...
Give it another turn and your problems will all go away I'm betting.
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Well, you were right. I had tightened it quite a lot, so I thought, but I forced it another turn... and it's been holding perfectly dry now for almost two days. I could probably have turned it even a little farther, but I was afraid that it would end pointing in a direction that would have made impossible to attach the water supply.
So, I was being a wuss. I guess I just needed to assert my masculinity, and I now feel more aggressive and hairier. Thanks!
Group hug!
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Nil wrote:

This is a not uncommon problem. I used to teach a PC hardware class in which one of the exercises was to install RAM. The women in the class always did better at it than the men because the women weren't afraid to put their weight on it when seating the SIMMs.
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You *can* break brass parts if you try hard enough, so don't use a pipe wrench with an "extension" on it.
However, it looks like very little of the Teflon tape made it inside the joint. Did you apply the tape so it went all the way out to the end thread on the elbow, or did you keep it back a ways from the end? Teflon that you can still see when the joint is screwed together is not doing you any good.
Another thought: look at the threads on the elbow and inside the solenoid valve. They should be smooth and clean, cut with a tap or die, with no obvious discontinuities (except at the thread start and end). I *have* seen Chinese-made compressed air parts that had die cast threads, and the mold separation lines still present in the threads prevented them from ever sealing properly.
    Dave
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On Jul 28, 1:18pm, snipped-for-privacy@cs.ubc.ca (Dave Martindale) wrote:

I'm with Dave, no tape on the hose side. In addition that brass elbow does not look like the correct elbow to connect to that hose or the valve.
The hose is a 3/8" compression hose, yes? The elbow should have a corresponding 3/8" compression end and an NPT end for going into the DW valve.
When the elbow is not screwed into the DW the portion that does screw into it should be tapered slightly. see here:
http://images.sector29.com/Large_Images/263/263-JAM4572DWSS.jpg
Notice that the end that goes into DW is slightly cone shaped. If yours is not it is wrong. If you did screw the wrong fitting in you can usually fix it by getting the right fitting and screwing it in with no tape to clean things up. Then install with tape.
The end that the hose screws to should look like the right hand side of this fitting:
http://www.scary-terry.com/ggshooter/comp_fitting.jpg
notice that the brass sleeve on the pipe does the sealing (rubber in your case).
I think if you get the correct elbow you'll be fine. check it out before you take a BFW to it and break something.
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Good advice above. But I'd skip the Teflon tape (it isn't a sealant) and use a real sealant like Permatex #3 (at any auto supply store). Likely the car you're driving right now has some of its vital fluids confined by this well known sealant. Teflon tape is a great thread lubricant, so use the right material for the job.
Joe
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alt.home.repair:

I took the tape off the water supply hose side and it's still good and dry.

I have two elbow fittings. The one that's in there now I bought when I thought I was going to use 3/8" copper tube and a compression fitting. I changed my mind and bought a flexible braided tube kit, so I could more easily work on the unit with it pulled away from the cabinet. That kit came with an elbow.
Now that you mention it, the kit elbow DOES look slightly tapered, although maybe not as much as the one in the picture. The other elbow is now installed and is screwed in hard and is not leaking, so I'm not going to mess with it any more. I don't know if it was tapered. But maybe this is a clue:
The installation book calls for a "90-degree elbow with 3/8" N.P.T. external threads." The elbow I bought at the hardware store was labeled "MPT". I asked the guy in the store if they were equivalent, and he said they were. Are they? Does NPT == MPT?

Big F-n' Wrench?
All seems well - I've got the dishwasher hooked up and have run a few loads. Everything is dry and seems solid. Thanks for your help.
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Two common pipe thread sizes exist, the tapered National Pipe Thread (NPT) and the straight National Standard Free-Fitting Straight Mechanical Pipe Thread (NPSM). The tapered threads are for joining and sealing, the straight threads are only for joining. The Dry-seal thread (NPTF) allows for joining without sealants. Three less common threads exist, the Garden Hose Thread (GHT), Fire Hose Coupling (NST) and British Standard Taper Pipe Thread (BSPT). The NPT and NPTF threads are interchangeable with sealants such as PTFE tape. None of the other thread standards are interchangeable. Female NPT threads can be designated as "FPT" and male NPT threads can be designated as "MPT."
from here: http://www.plumbingsupply.com/pipethreadsizing.html

Yes. Most things can be fixed with:
WD40 - loosens a BFW - tightens a BFH - adjusts duct tape - does everything else

Glad to hear all worked out.
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Limp Arbor wrote:

You forgot the gray paint. Covers damage from the BFW and the BFH, and if you put enough on maybe it will hold together until you get transferred.

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Close enough. NPT is National Pipe thread, Tapered, or something very close. (There's also NPS, same dimensions but Straight instead of tapered). The "M" in "MPT" means "male", so you'd expect the full acronym to be "MNPT". But somebody shortened it to "MPT"; dunno why.
    Dave

I expect so. It's closely related to the BFH needed for breaking concrete.
    Dave
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On Mon, 28 Jul 2008 14:08:02 -0500, Nil wrote:

The tape won't stop leaks but rather permit the joint to be tightened more.
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ana had written this in response to http://www.thestuccocompany.com/maintenance/Re-Dishwasher-hookup-leak-321845-.htm : Nill, I know it's been a while since this posting but I'm wondering if you got this fixed and how. I am now having the same problem. I have tighten both ends as much as they go without breaking and I still have a leak on the water supply hose side.
Thanks ana ------------------------------------- Napoleon Blownapart wrote:

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ana.barragan1_at_gmail_dot snipped-for-privacy@foo.com (ana) wrote in

Whatever seals, washers, compression washers, etc are there are probably destroyed. I'm no plumber and in fact have a lot of nads using the word. But after years of doing the common DIY'r plumbing mistake of overtightening, it finally sunk in. Many plumbing seals, once overtightened, are NG.
It's like cutting lumber. You can always cut it shorter - cut longer. You can always make it tighter - under tighten.
Tighten a fitting until you can feel the sealing surface make contact then just 1 nut facet (usually 1/6 turn) more...no not 1-1/2 and not 2. Don't even try to get it on the first try. Turn on supply, Plan on it leaking/dripping. If it doesn't leak DON'T snug it just for a good feeling. If it leaks then tighten it 1 more facet. Repeat until it stops. I'll often put a piece of paper towel under the fitting overnight for a warm fuzzy.
If this doesn't work then something is wrong with the seating surfaces.
The teflon tape is correct for what you're doing or you can use pipe dope. Make sure to get the one for water lines.     http://finehomebuilding.taunton.com/item/5094/whats-the-difference - joint-sealing-with-teflon-tape-and-pipe-dope
Compression fittings: Read the package. It will often say how much to tighten after contact. Do it just like it says. No more, no less. You can always tighten a hair if it leaks. These ESPECIALLY cannot be loosened and retightened.
PVC sink drain slip joint nuts. Don't even bring a pair of pliers under the sink. You might as well beat the whole damn thing with a brick before assembling. Hand tighten only. That's why many of them have a tab/wing...for your finger(s) to grip. Undertighten is safe. You can always make it tighter
Just my experience. A real plumber would go broke using this approach.
Red...
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p.s. Read the Comment at the bottom. It ends with:
    i occasionally had tightened teflon joints to the point of     distortion and was unable to make them stop leaking. never     had that problem with Pipe Dope.
    http://finehomebuilding.taunton.com/item/5094/whats-the-difference-joint-sealing-with-teflon-tape-and-pipe-dope
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ana wrote:

http://www.thestuccocompany.com/maintenance/Re-Dishwasher-hookup-leak-321845-.htm
If the valve side of the elbow is NPT threaded then TFE tape ought to prevent leaks, why don't you think it will on that side?
I agree that TFE tape on the threads probably won't stop leaks on the supply side, which appears to be a coned compression fitting.
But, I have stoped leaks on such fittings by wrapping TFE tape so it's on the angled cone sealing surface and then assembling the joint. I've done similar on compression fittings which "just won't seal" by wrapping the compression sleeve (aka ferrule) with TFE tape.
Unorthox, true. But the essence of pragmatism can be summed up as, "If it works, do it."
Jeff
Jeffry Wisnia (W1BSV + Brass Rat '57 EE) The speed of light is 1.8*10^12 furlongs per fortnight.

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