Betsy, my American Standard tank-style toilet, is moaning loudly for the first 5 seconds when flushing. I also hear that awful sound about once an hour when the tank is apparently being topped off, which leads me to believe the flapper valve is going. However, what's causing that sound? I doubt it's the flapper valve. Is the fill valve maybe also on its way out? The fill valve is a ca 6 year old HydroClean EZ aftermarket unit. I have never before heard such a sound from a toilet. I have left the lid off the tank and tried running there when I heard the noise, because I thought I would feel a vibration at the source, but I'm too slow. Since I leave this Saturday for my summer vacation, I need to figure out if should fix this now, or if I should just turn off the water supply before I leave and take care of the problem upon my return.