Hello, Glad I found this forum. My situation is this - I'm a commercial renter, and noticed that there was a squeaky and hissy sound emanating from one of the restroom toilets. There was also a slow steady trickle of water to the bowl. I asked the landlord to deal with it (since they've done it before and I had a similar problem with hissing/squeaking in the other restroom a couple years back), and they sent their plumber; I'm guessing he didn't want to be bothered, because he told my staff who were there at the time that he couldn't hear anything or see anything wrong. So I figured I would cut out the middle man and do it myself. Things I've done - replaced the fill valve - that stopped the hissing and squeaky sound replaced the flush valve - complete with new flapper, etc. replaced the two bolts/washers/gasket sets that hold the tank in place replaced the gasket fitting over the flush valve nut that holds it to the tank - it was one of those that had two "wing type" flanges that extend out from it (like a TIE Fighter in Star Wars) that the toilet tank bolts threaded through replaced the flush handle mechanism - we've done this multiple times, as they're always breaking (as I said, commercial renter, customers just wear and tear things to death) I did the dye test, and it does seem like there's a slight leak from the water in the tank to the bowl. Every ten minutes or so, the fill valve will run a tiny bit (about a second or two) and give it some more water inside the tank. The tank water level is sitting well below the top of the overflow pipe. I've tried adjusting the water level up and down, as well as regulating how much water was being allowed in from the valve in the wall. I adjusted the refill tube leading from the fill valve into the top of the overflow pipe. I thought it might be the flapper not closing properly, but if I reach into the tank and press down on it for an extended period of time, the water still slightly trickles to the tank. I can't for the life of me figure out what it might be - all the pieces internally have been replaced (fill and flush valve, etc.)...the only two possible ideas that I might have is that in the process of replacing the flush valve, I didn't get it seated or attached or put back together with a tight enough seal somewhere with the gaskets. (I though everything was pretty damned tight, but maybe not?) Either that, or somewhere in the body of the toilet itself, there's a hairline crack or leak - I do notice that the water only leaks out from the top inside rim of the bowl on the left side, and the right side remains dry, but when flushed, water is distributed evenly on both sides. Any help or ideas are appreciated. Sorry if the above is a long read - I wanted to give as much info as possible. Thanks!