Kohler GP1059291 canister seal
Fix a running Kohler canister toilet by replacing the canister seal
Many Kohler toilets have no flapper. Instead a cylinder-shaped canister lifts off the flush valve when you flush. Kohler's own service guide says that when this kind of toilet leaks into the bowl, you replace the seal on the canister, not the valve. The single-flush seal is GP1059291.
- SealGP1059291 (yellow)
- FitsKohler single-flush canister two-piece toilets
- Tank numberinside back wall of the tank
- Dual-flush seal1131496, a different part
Is it a canister valve?
- What you see
- Lift the lid. A tall cylinder in the middle of the tank, with a chain from the trip lever to its top, and no hinged rubber flapper at the bottom. Kohler calls this the AquaPiston canister flushing system and says most Kohler toilets use it.
- Single or dual flush
- A trip lever on the side means single flush: seal GP1059291. Two buttons on top of the tank means dual flush, which uses a different seal, 1131496, and a different procedure that this guide does not cover.
- Your model
- Kohler stamps the tank number on the inside back wall of the tank. Toilets made after 1990 also list service part numbers on the underside of the lid. Cimarron toilets, for example, use tank K-4634.
In Kohler's 2011 service parts matrix, GP1059291 is the seal listed for every single-flush canister two-piece model shown, including Cimarron, Archer, Bancroft, Cavata, Devonshire and Kelston. The GP prefix only means it comes in a blister pack; it is the same part as 1059291. It replaces Kohler's older red seal.
Seal, repair kit, or whole valve
- Seal GP1059291 stops a leak into the bowl. Start here.
- Canister repair kit GP1229656 adds a new cap, center guide and chain. Kohler recommends replacing the seal at the same time.
- Whole canister valve assembly: Kohler lists Cimarron versions by bowl outlet and flush volume (1083980 for a 3-inch outlet; 1188998 and 1216616 for 2-inch outlets with elongated bowls). Replacing the valve means taking the tank off the bowl, which this guide does not cover.
Aftermarket seals exist too: Korky's 451 is made to replace the original seal on Kohler AquaPiston toilets and fits a 3-inch canister opening, and Fluidmaster sells its 510K-001 for Kohler AquaPiston.
A Cimarron with a flapper rather than a canister uses a different flush valve (Kohler 1024385, with a 3-1/4 inch flapper).
| Item | Part | Number |
|---|---|---|
| 1 | Cap, center guide and chain to the trip lever | repair kit GP1229656 |
| 2 | Outer tower and overflow | part of the flush valve |
| 3 | Canister | part of the flush valve |
| 4 | Canister seal, fits the groove at the bottom of the canister | GP1059291 |
| 5 | Flush valve base on the tank floor | valve assembly, model specific |
Order by your tank number. Dual-flush canister seal is 1131496.
Tools and supplies
- Sponge and towel
- Soft cloth to clean the seat
- Food coloring for the dye test
Replace the canister seal
These steps follow the sequence in Kohler's own GP1059291 replacement video. No tools are needed for the seal itself.
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.
Disconnect the chain and refill hose
Unhook the trip lever chain from the lever arm and pull the refill hose off the top of the valve. Note where both went.
Take off the cap and center guide, then lift out the canister
Remove the canister cap and the center guide, then lift the canister up and out of the tower.
Swap the seal
Peel the old seal off the bottom of the canister. Press the new yellow seal into the groove so it sits flat and evenly all the way around. Wipe the seat it closes on with a soft cloth; Kohler notes that in-tank cleaners and water conditions wear flush valve parts.
Reassemble
Set the canister back in the tower, then the center guide and cap. Reconnect the refill hose to the top of the valve and the chain to the trip lever.
Set the chain slack
Kohler: the chain should have roughly one to two links of slack at most, enough that the seal is not held off the flush valve seat but not so much that spare chain catches on the lever arm.
Turn the water on, flush and dye-test
Open the stop slowly, let the tank fill and flush a few times. Check that the water stops at the waterline mark. Then add a few drops of food coloring to the tank and do not flush; color in the bowl after 10 minutes means the seal is still leaking.
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 |
|---|---|
| Fill valve turns on and off by itself | Water is leaking past the canister seal. Kohler: clean or replace the seal if it is worn, dirty or misaligned, and check chain slack. |
| Weak or incomplete flush | Check the refill hose is routed into the overflow or the top of the canister, and the water reaches the waterline mark. |
| No flush at all | Too much chain slack. Kohler: remove the slack, typically one or two links. |
| Still leaks with a new seal | The flush valve seat is damaged, or the flush valve gasket under the tank leaks. Both are tank-off repairs. |
| Two buttons on the lid | Dual-flush canister. It uses seal 1131496, not GP1059291. |
Official parts and warranty
Look up your toilet by the tank number on Kohler's service parts pages before ordering. Kohler's service parts guide lists the fill valve, flush valve and seal for each toilet model.