I just moved into my new house and I have a problem with the kitchen sink. When water is just running through the sink and pipes, there is no leaking. However, when I fill up the sink with water (say to soak pots) and then let the water out, the pipes underneath leak terribly as though the pipes can't support that volume of water being sent through them.

Also, I checked the pipes and one of them appears loose (I can twist it), but it's not come off and there doesn't appear to be any obvious signs of leaking otherwise.

Any advice?