The toilet flush valve on Kohler toilet brands is in the center of the toilet fill tank. The valve comprises five different components, including the lift rod or chain, a trip lever, flapper, flush valve seat and overflow pipe.
The lift rod or chain connects to the outside trip lever of the toilet and is responsible for initiating the flow of water into the toilet bowl during flushing. When the handle of the toilet is pressed down, the lift rod or chain lifts the rubber flapper that covers the flush valve seat hole that is set into the bottom of the toilet fill tank, which allows water to rush into the bowl. The flapper is unique to Kohler brand toilets and generic flapper replacements cannot substitute for it
The overflow tube component of the toilet flush valve is responsible for securing the valve flapper, as well as prevent water from overfilling the toilet fill tank and flooding the bathroom. As the water level in the fill tank increases, some of the water that rushes into the fill tank flows down the overflow tube and into the toilet bowl to refill it. As the water level continues to rise, the filler float that connects to the overflow tube rises until it turns off the toilet filler valve and cuts off the flow of water.