Think of it this way, fuel pump sucks the fuel forward, and hole will let in air. Check the short rubber hose at the tank to the steel fuel line, hard to check the steel line for a crack or rust hole the reason I suggested a LITTLE pressure, it will force any fuel out (need a helper for this). But if it has a hole being low it would form a puddle. If no puddle that lead back up to that short hose (I replaced a lot of those) if you change it don’t forget the small ground connector. All bubbles form before the pump. IF they are ok the line IN the tank is bad (I’ve seen them rust thru)