I have been bothered for a while by a leak somewhere in the water tank of the upstairs toilet. It is one of those leaks which causes the toilet to top of the tank once a day when it has no reason to. The noise of the water topping off the tank woke me at night a few times so I decided to act.
I shutted down the water supply, flushed the toilet and sponged the remaining water at the bottom of the tank. I suspected a worn flapper but boy, I was wrong! Here is a picture of the tank seen from above:
There are obvious signs of rust at bolts which attach the tank to the toilet and the head of the right bolt is almost completely gone, eaten by rust. It turns out that the installation was not done with brass bolts as it should have to reduce corrosion.
As with most plumbing projects, the most difficult is to remove the old. And that one was no exception. The left nut was relatively easy to remove (a few drops of WD-40 were enough to crack the nut). The head was not too damaged by rust so I could use a screwdriver (in the tank) and an adjustable wrench outside.
The right side was so rusty that the nut melted with the bolt. With the bolt’s head badly damaged by rust, my only possible option was to remove both rubber gaskets (inside and outside the tank) and then cut the bolt with a mini hacksaw equipped with a metal blade. That is when it became obvious it was not a brass bolt.
I inspected the hardware in the tank as well as the tank itself. I found a worn flapper and a large crack in the tank. The left picture shows the crack seen from the outside of the tank and the right picture shows the crack seen from the inside.
So I’ll be off to a few home centers to choose a new tank. Since the bowl itself is a little old as well, I might replace them both at the same time.