I was replacing the supply valves under my new bathroom sink as the old ones had old fashioned metal connectors that wouldn't work.
The old supply valves had a soldered on metal pipe right behind the knob, and I now realize (too late) that that was what I needed to unscrew (probably by cutting off the metal supply line to allow it to rotate). Instead, I turned a larger nut behind that, and directly in front of the flange against the wall. This turned seemingly forever, and once I realized it wasn't coming off (but was somehow coming out from the wall) I noticed that the pipe behind it seemed to have no threads. I started to get nervous that perhaps I was unscrewing a pipe deep inside the wall, so I started to turn the nut back in a clockwise direction (again, seemingly forever) but it never went back towards the edge of the flange.
Eventually I started to get a drip from this nut (just slight as the water for the house was turned off), and I found that at a particular position, this was minimized. A little bit clockwise and the leak became really bad, and the same if I went counter-clockwise.
I now have the water for the house back on, and a slow drip from this nut. I'm pretty nervous that something will give way, and I'll have a flood on my hands.
What have I done, and how can it be repaired?
Sorry this was so long, and hopefully, my description was clear- it's hard to describe without a diagram, but I'm wondering if I'll need to call in a professional to solder this fitting or what.
Thanks so much for any help that can be offered!
Andy

speedball1

Is this the angle stop that you're describing?

mega4

Here is a picture. I'm pretty sure I know what the problem was. Because the replacement simply screwed on, I assumed that was how the old one worked. After doing some research, I've come to the conclusion that I was dealing with a compression fitting, and needed to unscrew the back nut from the rest of the valve. It appears I haven't damaged the copper pipe below and can still do this once I get the PROPER part.
Does this seem to be correct?
Thanks,
Andy

speedball1

When you replace a compression stop you don't remove the old compression nut or the ferrule. You use them to install the new stop. Done correctly there should be no leaks and should be less then a 5 minute job. good luck, Tom