Are you talking about the wick cover/tube gasket? (right above the bottom of coil and surrounding the pipe?) if so, yeah.. you need that in there, you also have to be careful how are you tighten it. That gasket covers the wicks, and if it's too tight it will restrict flow to the wick. It will take a few minutes for the fill to wick in where it's supposed to, and if you go too soon you will get dry hits.