Fluidmaster 5403 / Korky 3060BP
Replace a 3-inch toilet flapper on a newer low-flow toilet
Many newer 1.28 and 1.6 gallon toilets use a 3-inch flush valve and a larger flapper, about 4 inches across. A 2-inch flapper will not seal it. Measure before you buy, then fit and tune the new flapper so the tank stops seeping into the bowl.
- Drain openingabout 3.5 in
- Old flapper acrossabout 4 in
- Chain slackabout 1/2 in
- Replaceat least every 5 years (EPA)
Is yours a 3-inch flapper?
Flush valve size is set by the hole the porcelain maker bored through the bottom of the tank, so measure rather than guess.
- Drain opening about 3.5 inches across: 3-inch flapper.
- Old flapper about 4 inches from end to end: 3-inch flapper.
- Does it look like a tall cylinder or a tower instead of a hinged rubber disc? You have a Kohler canister or an American Standard Champion 4, and need a different part.
Not sure? Measure the other way too: the 2-inch flapper guide covers the other size.
Which flapper to buy
- Fluidmaster 5403
- Universal adjustable 3-inch flapper with a silicone seal and solid frame. Fluidmaster names American Standard, Kohler Cimarron and TOTO toilets, rates it for 1.28 and 1.6 gallon toilets made after 1994, and gives a ten-year warranty.
- Fluidmaster 5401
- A direct replacement for Glacier Bay and American Standard toilets that came with the 540 flapper and flush system.
- Korky 3060 (also sold as 3060BP)
- Korky's 3-inch premium universal flapper, for 3-inch flush valves in 1.6 and 1.28 gallon toilets made since 2005. Adjustable, five-year warranty. The Korky 3070 is the ten-year version.
Fluidmaster makes 3-inch flappers only in a solid frame. Brands such as Kohler, American Standard and TOTO build both 2-inch and 3-inch toilets, so the brand alone does not tell you the size: measure.
| Item | Part | Number |
|---|---|---|
| 1 | 3-inch flapper on the flush valve seat | Fluidmaster 5403 / Korky 3060BP |
| 2 | Overflow pipe with mounting ears | part of the flush valve |
| 3 | Lift chain | comes with the flapper |
| 4 | Tank lever arm | reuse |
Check the maker's fit list against your toilet model before buying.
Tools and supplies
- Sponge and towel
- Clean cloth for the seat
- Food coloring for the dye test
- Scissors or pliers to trim chain
Replace the 3-inch flapper
Close the stop valve behind the toilet and empty the tank
Turn the stop valve on the wall or floor behind the toilet clockwise until it is snug. Flush and hold the handle down to drain the tank, then sponge out the water left in the bottom. If the tank starts refilling, the stop is not holding.
Safety: Do not force a stop valve that will not turn; old stops can break or start leaking at the stem. Use the house main instead.
Measure to confirm the size
With the tank empty, measure the drain opening the flapper covers. Fluidmaster: an opening of about 2.5 inches takes a 2-inch flapper, about 3.5 inches takes a 3-inch. Or measure the old flapper end to end: about 3 inches across is a 2-inch flapper, about 4 inches is a 3-inch. Yours should be about 3.5 inches and 4 inches.
Unhook the chain and remove the old flapper
Unclip the chain from the tank lever. Unhook the flapper's arms from the mounting posts on the overflow pipe, or lift them off if it has a solid frame. Take it with you if you are buying the part today.
Clean and feel the seat
Wipe slime and grit off the flush valve seat with a clean cloth, then run a finger around the rim. A nick, chip or rough patch there will leak under any flapper and means the flush valve needs repair or replacement.
Fit the new flapper
Remove any cardboard packing from under the new flapper. Set it on the seat and snap its arms onto the mounting posts. On wider flush valves, push the arms out to the "B" setting. Lift and lower it by hand: it should drop squarely onto the seat and move freely.
Attach the chain with a little slack
Clip the chain to the hole on the tank lever directly above the flapper. Fluidmaster's guide is about 1/2 inch of slack with the flapper closed, a small J shape. Too tight holds the flapper off its seat; too loose gives a weak flush or lets the chain get caught under the flapper. Use the old chain length as a guide and cut off spare chain that could tangle.
Turn the water on and tune the flush
On the Fluidmaster 5403, set the dial to 10 and flush. Turn it down one setting at a time until the toilet will not flush properly, then go back up one. Fluidmaster's 5403 sheet also lists dial settings and chain lengths for specific toilet models. On the Korky 3060, turn the white band to a higher number if you have to hold the handle down to finish a flush.
Dye-test it
With the tank full, add a few drops of food coloring and do not flush. If color appears in the bowl after 10 minutes, the flapper or seat is still leaking: recheck the chain and seat. Flush when you are done so the dye does not stain.
Stop and call a plumber if
- The stop valve behind the toilet will not close, or it drips at the stem or the nut once you have moved it.
- The supply line is corroded, kinked, bulging, or a braided line shows broken strands. Fluidmaster's own sheets say to replace a supply connector that is worn or over five years old.
- Water is on the floor around the base of the toilet, or the floor near it feels soft. That points to the wax ring or flange, which means pulling the toilet.
- Water drips from the tank bolts or between the tank and bowl. Fixing that, or replacing the whole flush valve, means taking the tank off the bowl.
- You see a crack in the tank or bowl porcelain, even a hairline one.
- The flush valve seat itself is chipped or pitted and a new flapper still leaks.
Troubleshooting by symptom
| What you see | Likely cause and fix |
|---|---|
| Dye shows in the bowl after 10 minutes | Flapper not sealing. Check chain slack, clean the seat, feel for nicks. A flapper older than five years: replace it. |
| Toilet refills by itself (ghost flushing) | Water is leaking out of the tank. Check that the refill tube is clipped above the overflow pipe and not pushed into it, then the flapper. |
| You have to hold the handle down to flush | Chain too slack or the dial set too low. Shorten the chain a link or two, or turn the dial up. |
| Weak flush that leaves paper | Dial set too low. Turn it up one number at a time. |
| New flapper warped quickly | Fluidmaster blames chlorine tablets in the tank for warped flappers. Remove them. |
| Still leaks with a new flapper and a clean seat | The flush valve seat or gasket is worn. Fluidmaster's next step is a new flush valve, which means taking the tank off the bowl. |
Official parts and warranty
Fluidmaster gives the 5403 a ten-year warranty; Korky's 3060 carries five years and the 3070 ten.