American Standard Flush Valve Assembly 1.28 Gpf - AMS-738921-104

Order it by American Standard part number 738921-104.0070A. It is the complete flush valve assembly for 1.28 gallon-per-flush toilets, not just a flapper, so it covers the valve body, the 1.28 GPF refill, and the flapper together.

It is built as a 1.28 GPF assembly, with a refill rate metered for 1.28 gallon flushes and a blue-coded flapper matched to that volume. Putting it in a 1.6 gallon tank can leave you with a flush that does not clear the bowl, because the tank's water level and trapway were engineered around the larger volume. Match the assembly to the rated flush volume stamped on the toilet.

Yes. The assembly ships with an adjustable water-saving flapper, so you can tune how long the flapper stays open and trim the water used per flush. That is the adjustment property managers reach for when a building's toilets are running long or double-flushing.

If the flapper seat itself is scored, pitted, or warped, a new flapper alone will keep leaking, and that is when you replace the full valve. This American Standard assembly is a complete 1.28 GPF flush valve, flapper included, so it addresses both the seal and the seat in one part. If the seat is clean and smooth, a flapper on its own can be enough.

No. What you get is the flush valve assembly itself with the 1.28 GPF refill and the adjustable flapper. The fill valve, tank-to-bowl bolts, tank gasket, supply line, and trip lever are separate items, so order them alongside if you are rebuilding a tank completely rather than swapping one failed component.

It does. American Standard uses the blue flapper to identify its 1.28 GPF service parts, so if the toilet you are servicing came with a blue flapper, this assembly is the matching flush volume. A flapper in a different color on that model usually means someone fitted a part from a different flush rating.