Going through a carb that has sat for many years, and the pump seems loose in the bore. I let it soak in gas for 10 minutes or so thinking it would expand some, and it seemed to a bit, but was still loose, and when I put gas in the well and pushed down on it, it just squiged out the side, and didn't go up through the nozzle.

Do these things shrink over time? Is it time for a new one, or will it expand out a bit after sitting in gas?