I've had a steadily growing leak in the bathroom, in the general vicinity of the toilet. Since I was totally distracted with work, and initially thought it might be Maggie being naughty to get my attention (not to mention I usually put my shoes on first thing to avoid Maggie pouncing on my toes), it has taken me a while to really track the source down. It's at the top of this joint (where the whole works connects into the tank) and it's now throwing about 2 quarts a day (I emptied out the second litter box, as Maggie does not use it).
The toilet works as normal; it's just apparently leaky. Although sometimes I hear "plumbing" (water-moving) noises when I know I'm not operating any water-using devices in the house.
What may be causing it and what should I do?