Chicovt You must be careful when the gasket enters the canister, it will always try to push a part (lip) of the gasket to the top. I bring the plunger down until the gasket just touches the canister. I then check all the way around to see if the gasket is faceing down. When not I take my fingernail and go aruond the canister pushing the gasket in position. it usualy is about a fith of the dia.