Hello everyone! This is my first post but I've been lurking for a long time. Now is the time I need to ask for help as I don't see a similar post so far as I can tell. Here's the situation; there is a leak behind the wall of my bathroom. I know this because the sheetrock underneath the sink has been removed since I bought the house and I can see it dripping water. I can't tell what's causing it though. There are two pipes there; one is the vent/drain for the sink and then there's another vent pipe to the left of it that is right next to it that I'm only guessing is a vent pipe? There is a small hole in it which is why I say that. In looking up into the wall, so far as I can tell, there is a P-trap on the pipe on the left and then they both go up into the attic where they then join together, make a 90 degree angle, join the toilet vent pipe then go up through the roof. In the problem bathroom, there is a toilet right next to it. I had installed new internal guts (a BlueSource HydroFix Water Saving Toilet Fill Valve and Flapper Kit by MJSI) a few months ago and ever since then, I notice that the water level inside the bowl gets really low after a little bit of time and when I flush it, a big air bubble comes out and it flushes fine. I never thought anything of it but now it concerns me and am wondering if the two are related. I can't really say if it leaks when I flush the toilet or when I turn the sink on since there's a delay between the two and it's not like it's gushing water; it's just a small drip that stops after a small while. I read through many of the posts here about air in the system which is why I ask. Any suggestions? Do I need to make a whole in the wall to investigate? Being that the leak is up inside the wall, I'm worried it's an actual leak over something being clogged because I wouldn't think it would leak where I'm seeing it. Any help would be appreciated!!



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