One of the toilet tanks in my house is leaking water slowly into the toilet bowl. A pic of the inside of the tank is attached. I believe a gasket is the culprit (the pink gasket pointed to by the red arrow in the pic), but I can't figure out how to remove all the black parts above that gasket to get to and replace the gasket. I tried pulling on and twisting the small part above the white ring to release the cylindrical part (which slides up and down) to which the gasket is secured but no success. Can someone please advise? Or, do I have to somehow unscrew the entire assembly (at the joint pointed to by the green arrow)?


Toilet tank

1 Answer 1


That is a Kohler "canister style" flush valve.

First, carefully remove the "rim-clean/bowl-fill" water supply hose (the little black hose that runs from your fill valve to the flush valve. Also, remove the chain that attaches the trip lever to the flush valve.

To get at the gasket in question (which is very likely, but not 100% certainly, your problem) you need to carefully twist the "small part above the white ring" counter-clockwise 1/4 turn. This will release the entire canister assembly from the base. It will look like this (note chain still attached in my pic):

enter image description here

The pink washer on the bottom just stretches and pulls on/off. Reverse previous step to reinstall...

NOTE- I have performed this job without removing the hose and chain, but it is easier with them removed.

screen-shot courtesy of [email protected]

  • 1
    Thank you - much appreciated. The "small part above the white ring" seemed too tight to turn in my case so I had to slightly raise the cylindrical part with one hand, reach down under it with the other hand, and turn the center shaft to release the canister assembly. The gasket actually seemed alright, but really old and dirty, so I took the gasket out, measured its dimensions, cleaned it, and put it back. If the problem persists I'll replace the gasket. Sep 8, 2019 at 21:03
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    When I did not have a new gasket immediately available, I have had some (temporary) luck with cleaning it and flipping it over... Sep 8, 2019 at 22:39
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    Thank you all. This helped me replace the gasket in my tank as it was falling to pieces and our tank was constantly leaking into the bowl. I don't know anything about toilets so if I could do it then anyone can do it. Oct 7, 2022 at 21:32

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