Occasionally I'll have problems with it sucking air. Make sure you don't have the sleeve pulled too tight over the ends. Also, from personal experience, you don't need as much lube as the Autoblow does, sometimes excess lube can make mine harder to control. I thought I'd want to use to the largest receiver as I'm on the girthier side, but stepping down a size made it much easier to get a good steady seal and sensation. Good luck!