An easy way to check your seal is to open the top about 3 inches and let it go. You should hear a "whooshing" sound as the top closes. If it slams shut with a bang, then you need to check your seal. Put a dollar bill(or whatever goofy money you use up there

) between the top and the bottom in several places. If you find a spot where it slides out easily, then use the magic blue(painters)tape to seal.