Cold water shut-off valve off, still dripping from hose

[Josee]

I am attempting to replace a powder room faucet which had a drip caused by a cracked cartridge. I shut off the hot+cold water supply under the sink. I still have a steady (every 3-4 seconds) drip from the cold water and its not just what's left in the hose.
When I removed the old fixture there was quite a bit of water in the holes where the cartridges were and there has been leaking so that around the fixture holes on the underside of my sink there's water damage and the particle board is blackened. We intend on changing that vanity eventually but am wishing to dry it out for now.

Question: What do I do about the dripping shut-off valve? Would that dripping have been the cause of the damage (and will it continue) or did my cracked faucet cartridge cause that?

Many thanks again!

 

[Terry]

The cracked faucet cartridge was the leak that mattered, now you have a leaking shutoff that is only discovered because the supply line is disconnected. You can either pick up a 1/2" threaded cap for the supply line, or replace the shutoff. Often we find that it's the hot side shutoff that fails first.

 

[Sponsor]

 

[Josee]

Thank You! I imagine I have to shut-off the main water supply (once I locate it...)?

Is it the blue or red part I must change:

 

[Terry]

I'm surprised that what you have isn't shutting off.
It looks to be a Dahl brand that fits 3/8" compression female by 3/8" compression male. It just unthreads, both the red and the blue.
The picture below is similar, but not the exact one. Yours is a straight stop.

 

[Reach4]

I am not a plumber. I would try to tighten up the leaking nuts. What I don't know is if the bottom nut in the red box is fixed to the valve body body, or if the nut turns independently of the body.

If independent, I would tighten the red nut while holding that bottom piece. Then I would tighten the nut in the blue box while holding the valve body. Those may need a 5/8 inch wrench, but I am not sure.

If not independent. I would hold the bottom piece, and turn the blue nut only. I would then expect the valve to rotate and both nuts to tighten. Somebody will probably know which case applies.

You might turn each nut 1/4 turn more. Maybe it will take more or less.

 

[Josee]

Here's another angle

 

[Jadnashua]

The nut next to the supply hose is part of the hose assembly. It's always a good idea to change those out when changing the valve. You do NOT use any tape or pipe dope on the threads with that hose.

The valve itself appears to be a threaded valve, so it will just unscrew from the fitting below it (after removing the hose on the top). You WILL need either pipe dope or tape (or both, if you prefer) on the threads to make that seal between the valve and the fitting. What you may find is that if you take the valve off, then clean up the threads and install some new tape or pipe dope, that joint will stop leaking. If you moved that during the work, that may be why it is leaking.

If the valve itself is cracked, you must replace the valve. If it's leaking around the stem of the part that shuts it off, on that type, you can't fix it, and you need a new valve.

Yes, you do need to shut the main water off to the house BEFORE you remove that valve.

 

[Gary Swart]

Get a new valve.

 

[Dj2]

Question: What do I do about the dripping shut-off valve? Would that dripping have been the cause of the damage (and will it continue) or did my cracked faucet cartridge cause that?

Answer: Dripping shut off valves (aka angle stops) should be replaced of course. You will need to shut the main for that. Changing these valves and supply connectors should be almost automatic with every faucet repair (the cheapest insurance you can get for a few dollars).
About the damage: the damage is caused by water, so blame the source of the leak for the damage.