You can find most toilet leaks by going into the bathroom, turning off any appliances that are making noise and closing the bathroom door. If you hear a water source flowing around the area of the plumbing of your toilet, you can be pretty sure you have a toilet that is leaking. To be certain that the leak is a toilet leak, add some drops of liquid food coloring into the toilet tank and wait about ten or fifteen minutes. If any of the food coloring is in the toilet bowl, you have a certified leaking toilet tank. The most common cause for the toilet tank leaking is a faulty toilet bowl flapper. The flapper is what holds fresh water in the toilet tank until the toilet is flushed. Replacing the toilet flapper is a common repair. To replace a toilet flapper, just unhook the chain at the flush lever, carefully pull the flapper out of the bracket it is locked into and replace with a new flapper of the correct size. Another common reason for toilet leaks is that there is too much tension on the toilet lever chain. If you look in the toilet tank, you will see a chain attached to the toilet lever. If this chain is too tight, which in turn will hold the flapper away from its seal, then you can loosen the chain until the flapper seats on its seal properly. Hopefully one of these solutions will have solved your toilet leak repair.