H3's sometimes become possessed at the pump. In order to exorcise the fuel deamons, I start at a slow fill rate. After about 30 seconds, I can begin to increase the fill rate, usually to full speed.

I also raise the coach on the side from which I am filling and don't open the opposing fill cap.

I know that this all sounds weird but it was a lot better than the guy in the Liberty XLII next to me who was out in front of his coach drawing pentangles on the ground, casting eye of newt, and sacrificing lambs all while beseeching the maker "Hello, can you hear me now?".