Dodge has a huge problem with this my Dodge Nitro had this problem after many times to the dealership they replaced the fuel tank. There is a check valve that isn't working properly. I told the dealership while it was still under warranty to replace the tank but they have to follow certain steps. Here is a video of what happens. It wasn't the pump I was using it happened at all of them I used. skip ahead to 50 seconds and you will see.