Some toilet models do not have the ridge; instead, they have a rubber support to give the tank some stability. I replaced the guts of my toilet (second one) with standard Fluidm**ster replacement kit. The wingnuts securing the 2 parts are rusted solid. The main bathroom toilet had silicon all around the join and the owner said there was a crack and it had been leaking, he said he wanted to save it. The ridge is about ¼â€ higher porcelain either the tank or bowl surface that the other rests on for stability. As the water begins filling the toilet’s tank, check for leaks around the new valve. Here is a picture of the actual leaking bolt from the back bottom of the toilet. Toilet tank leaking on the floor after removing and reinserting flush valve. Flush the toilet (to remove as much water as possible) then undo these wing nuts, take the lid off the cistern and see if there are a couple of screws holding it back to the wall. Disconnect the toilet supply line from the toilet. Tighten the wing nuts down until the tank and bowl touch. Remove water line from back of toilet. If leaks occur when you flush the tank, the problem is the “Tank to Bowl” Gasket. Shut off the water at the valve and drain the water from the toilet tank, as indicated above. When I took the cistern off 3 pieces fell off the pan beneath, it was not just cracked but broken and held together with silicon. Make sure the tank and bowl are touching the “ridge”. While a nut cracker would be difficult to apply to a wingnut, much less under a toilet tank, a pair of locking pliers or similar "high force" tool should be able to break (crush) the plastic nut so you can get the rusted bolts out. Remember to place the sponge rubber gasket before placing the tank in the bowl. Use a sponge to absorb the remaining water out of the holding tank. It only leaks down the bolts that connect the reservoir to the bowl. I would pull the assembly away from the toilet and it would leak. Flush toilet and sponge out water from tank. And I can't get it to stop leaking but only when I flush the toilet. There should be another one on the opposite side of the cistern too. I gently moved the assemble as far forward towards the toilet seat as possible and then tightened the knobs. Whether water is leaking into the bowl or onto the floor, some plumbing work will be required to fix it. If there is, undo these. This is usually located on the bottom left hand side of the toilet’s holding tank. 1 has broken when I tried to turn it, the other won't loosen and when it does, the bolt moves at the same time as the nut ! Tighten the wing nuts down until the bowl and tank touch. Flush the toilet to empty all of the water in the toilet’s holding tank. A leaky toilet tank never feels like a simple problem to deal with. I don't get it. 3. To fix a toilet that has the same problem as above: First turn off water. Remove the top cover on the toilet’s holding tank and set aside. I've replaced the flange gasket several times. More advanced phases of curing a toilet leaking from the base will require moving the toilet itself. 2. Then, see the wing nut next to the water inlet? It does not leak between the bowl and the reservoir. Use a plunger to force out any water that remains in the bowl. If there is a leak, shut off the water, empty the lines, and unscrew the valve’s compression nut. If I did the sequence in reverse and tightened the assembly to the plate, and then the plate to the toilet. You may require a smaller or larger gasket to seal the leak. I then tightened the wing nuts to secure the plate. toilet - rusted wingnuts I need to separate the cistern from the bowl to replace the doughnut ring. Remove the 2 or 3 bolts holding toilet … Related.