Home Plumbing question - leaky supply

In My Humble Opinion
1

I decided to replace my faucet and drains in the bathroom sink. First time sink plumbing. It took me like 5 hours.

Final problem is that the supply line for the cold water is leaking at the connection to the valve. The leak stops when I turn the valve off, so the valve works. The supply line didn’t leak before I started this whole thing. I replaced it with a new braided metal one.

I tried tightening it. I tried re-connecting it and tightening it again. Still leaky.

Should I tighten it more? It’s not really going more. I also do not have the strongest arms so maybe it’s not “dad tight.”

Should I assume I somehow borked the rubber gasket and get a new one? Is there some other point of failure (such as the collar)?

Everything I’ve read says tape is not the answer. Also everything I’ve read says both “Don’t over tighten it” and “tighten it some more.”

2

Turn the valve off and disconnect the line from it. Look at the connection, there’s a rubber gasket on the inside. Is there any debris in there preventing a good seal?

Under sinks can be really tough to get proper leverage but if you can, use a longer wrench or some long bent-nose pliers (wrap the Jaws with duct tape to prevent marring the nut) to try to get more leverage. Leverage beats strength.

3

Also it is possible you’ve cross-threaded the connection? It should have started out really easy to turn for at least 3 or 4 turns then got difficult once it started to seal. If it was difficult the whole time, you may have misaligned the threads. Depending on the valve, it may need to be replaced if that happened.

4

It feels really good and turns easy.

I took a look at the gasket and it seems fine but I can check again.

Are you going with “tighten it more”?

5

I’m a half-assed plumber, but always end up with a good result. In your situation I’d grab for my Teflon tape and give that a go.

6

Teflon tape is not needed on a compression fitting and can interfere with proper sealing. I suspect @crazyjoe is correct about either a split gasket or cross-threading.

Supply lines should be hand-tightened and then wrenched about 1/2 a turn.

7

Six bucks will get me a second chance at a clean connection. I think I will try buying a new one and tightening it less.

8

I went in there and gave it one more turn for glory and it started spraying not just dripping, so I’m guessing I borked the gasket. New line it is.

9

Dave Barry (paraphrasing): The only way to keep a plumbing part from leaking is to tighten it until it breaks. :wink:

10

Can you link to the type of valve and hose you purchased. Unless you broke something, I wouldn’t have expected spraying.

11

I’ll disagree with the half-turn after hand tightening recommendation… At least in my experience it’s always taken more than that to make a good seal. But probably not more than a full turn.

12

I got this

https://www.homedepot.com/p/BrassCraft-3-8-in-Compression-x-1-2-in-FIP-x-20-in-Braided-Polymer-Faucet-Supply-Line-B1-20A-F/100459572

Honest to Og, started spraying. I can’t really see well enough to tell you if the washer was messed up when I took it off. It’s in the trash now.

I got the new one and put it in. Hand tightened and a bit of a turn with the wrench. Of course this time the faucet end decided to leak but I had threaded so lightly (ha!) that I had some room to tighten.

So…I’m slightly confident my plumbing career is over for another 10 years! :crossed_fingers:

13

As they say in the plumbing biz: All’s well that ends dry … After it made a wet mess. :wink: