I recently installed a new shutoff under my sink and it has a 3/8 compression fitting for my dishwasher. I want to cap off the fitting until my dishwasher gets here.
The problem is I can't get the cap to seal. I purchased a 3/8 compression cap and applied teflon paste to the 3/8 outlet on the shutoff valve.
Am I missing something? The guy at menards confirmed that I can use a compression cap to seal off the outlet. Is he wrong?
Thanks for the help!
Why not just shutoff the valve until the dishwasher gets there? Unless you only have one shutoff for the faucet and dishwasher, in which case I'd add another valve. The more knowledgeable plumbers may disagree, but you can never have enough shutoffs. I'v only been in my current house about 6 months and have already add/replaced 8 of them.
Did you put the ferrule inside the cap before you installed it? if not that's whats causing the leak...good luck.
No I didn't. I specifically asked the guy at Menards and he said I wasn't supposed to use one (one did not come with the cap). Are you certain it is required? I hope so, because that would solve my problem.
Thanks for the help!!!
Ben wrote: Did you put the ferrule inside the cap before you installed it? if not that's whats causing the leak...good luck.
If it's really a "cap" it won't need a ferrule. Try some teflon tape over the paste, and don't overtighten. Tom
Some caps have a rubber gasket inside, does yours? Can you add one cut from some other piece of rubber?
The cap does not have a rubber gasket. What bothers me is that nothing else came in the package. The package said 3/8 compression cap. It is the same thread as the compression outlet on the shutoff. Should I just keep tighting it down? I better judgement tells me that is not a good idea.
It should be tight enough to offer_some_ resistance to your smaller wrenches, at least. Tighten incrementally, check for leaks at each increment. Tom
I've put several of those caps on unused fittings around here. All of them have rubber gaskets inside, such that the gasket will compress between the cap and the end of the outlet. The gasket is just a simple rubber disk that fits inside the cap.
Currently I have four in use, purchased at two different times. I think all from Home Depot, but it is entirely possible a pair came from Ace Hardware. Ace Hardware also sells rubber sheets (about 5x7in) in a bag which are intended to make gaskets. I would make a gasket rather than continue cranking down on the cap.
sdb
Thanks sylvan! I will give it a try.
replying to Dave, Barb Villa wrote: I just learned the VERY hard way that apparently there are TWO SIZES for a 3/8 compression cap...one is marked OS on the package the other IS. I was given the OS one and had the same issue as you did(yup...12 years later)...fortunately an old plumber friend arrived nearby and explained this to me and gave me one of HIS IS ones...that had already been fitted with a rubber disk which sealed off the outlet perfectly. Lots of time wasted in ALL of the big box stores. Teflon tape is irrelevant. Someone posted that Home Depot still sold these units with a rubber ring included in the cap. The display at my nearby store showed that. NONE of the for sale inventory had it. My plumber confirmed this is now the new "normal"...someone needs to let the store personnel know...or the manufacturers to clarify. Could be that China ran out of rubber?! DAYS of my life lost on this stupidity! Be sure to check for OS versus IS on the package when you buy.
replying to Barb Villa, Petrov wrote: This was super helpful folks... Same issue the Tomahawk 3/8" compression cap I got from the Home Depot. I put it on - not to over tighten and it just plain old leaked. Then did the usual Internet search and found this forum and looked for old rubber hose. Found some - fashioned a round disc and wedged it in the cap. Threaded on the Cap and Rubber disc and no more leaks. Worked like a charm! I guess the fella at Home Depot has not done done a job like this - I'll have to write a review on their Website. Thanks All!
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