If the leak in the primer pump was bad enough I would think you could draw more air into the system.Did you put the two filter seals up to each other?Make sure the rubber seal on the old screw on filter matches the new one.Different brand filters can have slightly different diameter cans but as long as the ports match up and the seal on the bottom it should be good.When I changed my fuel filters last the big bolt on the top of the can leaked for a little while tightened it up and i was good to go.