Need more info. Where's it leaking? On the bottom of the tank? Where specifically? Have you checked to see if the screws/bolts attaching the fuel pump to the tank are tight?
Are you sure it's a 'sucking' noise you are hearing and not a 'air escaping noise'? Either one are most likely caused by plugged fuel tank venting system. Which could be a pinched or debris blocked vent hose as spalkin alluded to, or more likely, the orange rubber grommet under your fuel tank cap is misaligned and blocking venting as Wolfhound mentioned.
Never heard of a leaking fuel pump before.
We need more specific info to help you figure out what's going on