Stranger still:These SUs

[RazorBobSr@aol.com]

If I let the eng run till filters are empty,and then pop the tops of fuel 
bowls off,I get a LOT of strange sucking sounds like a vac being releaced,I NO 
understand this AT ALL.All of these things happen weather I use mech pump or 
elect!!!! Need some help guys???? Bob A