Toto Tank-to-Bowl Gasket Set (10-Pack) for G-Max/E-Max Toilets

The THU131 is a 10-piece tank-to-bowl gasket set, so it's a bulk pack rather than a single repair kit. That quantity suits a maintenance shop or property manager stocking a shelf for multiple toilets rather than someone fixing one leak.

Water at the floor around the base is usually the wax ring under the bowl's horn. Water running down the outside of the bowl from the seam where the tank meets it, or pooling on the bowl's rear shelf, points at the tank-to-bowl gasket. The THU131 set covers the second case only. If the seepage only shows up during and just after a flush, the tank-to-bowl seal is the likely culprit; a constant wet spot at the floor is not.

It's the sponge gasket that sits between the bottom of the toilet tank and the top of the bowl, sealing the flush passage where water drops from the tank into the bowl. When that gasket hardens or takes a set, you get water weeping down the back of the bowl onto the floor every flush, which reads like a cracked tank but is usually just the gasket. The THU131 is a toilet tank part, not a supply-line or wax ring component.

Yes. The gasket is captured between tank and bowl, so the tank has to come off: shut the supply, drain the tank, disconnect the supply line, back off the tank-to-bowl bolts, lift the tank clear, swap the gasket, then reseat and retorque evenly by hand so the china isn't stressed. Budget for replacing the tank bolts and their washers at the same time, since those are a separate part from this gasket set.

Order Toto THU131. That's the manufacturer part number for the 10-piece tank-to-bowl gasket set, and it's the number to quote on a purchase order or hand to a counter for a multi-unit building stock.