Not getting a good seal on 2 liter fliptop growler
 

I recently acquired one of those German 2 liter fliptop growlers. I had to buy a new assembly (flip top, hinge, and gasket) at my LBHS. The seal isn't good enough, as there is a bit too much play in the mechanism. I get bubbling at the gasket when I fill it. Has anyone had similar problems with these?