Spouse and I are installing a brand new Kohler 3 handle tub/shower manifold. Hot side had no leaks when we pressure tested. The cold side has a very small leak around the big compression nut. We tried incrementally tightening, but no matter how much we tighten it still leaked. We actually changed out the brass compression fitting on that side (we used the 1/2" threaded version and used plenty of Teflon tape on the 1/2" copper fitting that threaded into it) but it still has the small leak. Is there something we are doing wrong? Or a way to stop a small leak on the compression fitting? Or is the manifold some how defective? Both surfaces of the compression fitting seem fine by visual inspection, no pits, scratches, or burrs that we can see.
BTW we have a pressure balancing valve pre-inline so the manifold meets code.

Some times a little pipe dope between the Ferrell and faucet side of the compression fitting helps, but first the Ferrell is seated into the fitting properly ,or maybe the leak is just above where you think it is

ferrule

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

Kohler doesn't call this part a ferrule. They call it a "union Joint". There are none of the brass ring things that I associate with being ferrules. Like I said the manifold is brand new. What would a plumber do if confronted with a compression joint which won't seal?

aaah-ha

it is not a compression joint, soooo no ferrule (i was being funny re: spelling)

it is a mechanical union joint - seals metal to union using a 'ring'


check mating surfaces for 'burrs' or roughness or dirt

check that the connection is 'square', even, and 'touches' before need to tighen (proper alignment is critical)

a touch of lubricant (nevr-seez) on the threads (part 29) and the back 'shoulder' of the male end (part 28) where part 29 turns and 'scrapes' to enable tightening would be a very good thing

[www.us.kohler.com]

PROPER ALIGNMENT IS CRITICAL FOR PROPER "ENGAGEMENT"

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638



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Hubby and I will try again. We've already inspected the mating surfaces and no problems could be seen. We'll try the anti-seeze on the threads (they are very tight). We lubricated before with soap.

AND on the 'shoulder' where the 'capture nut' turns to tighten the 'spud'

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

If you are using the correct terms, a "plumber" would probably NOT be using that type of fitting in that location. If you are referring to a union which is part of the fixture itself, then pipe dope on the mating surfaces is all I have ever used.



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Those are the fittings that came with the manifold. Not by my choice. If you are questioning the terms, I guess plumbers don't call these compression fittings (as a previous poster noted), but rather union joints. I just thought that they would be considered a type of compression fittings as the principle is compressing the two metal faces together enough to make a watertight seal.



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We used the anti-seeze on the threads and shoulder as advised, and so far, 1 hour later, NO LEAKS! Thank you!...Oops.
Spoke too soon. small oozing noted out of both sides. Hubby tightened them about 1/8 turn. We'll see what happens. Cross my fingers.



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Finally 12 hours without leaks!



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go another 1/16 turn and "button 'er up" after 2 hours


good job

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638



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Thank you so much. My husband had to put everything he has into tightening. Without the anti-seeze I doubt he would have gotten it snugged up enough.



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'every thing he has' is a very very relative term

i am, personally, a relative weakling and always depended on proper alignment to ensure proper engagement of unions w/o using gorilla strength

if the parts were clean and 'nick free' AND properly aligned (they should NOT have needed pulling into place) they should have mated with relative ease ESPECIALLY if neva-seezed


perhaps y'all should get a pro to remake this final MECHANICAL connection and correct any misalignment found


best of luck

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638



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