A breast pump is one you want on hand, not buried in a truck, so keep it in a personal bag and make sure every part is bone dry before it goes anywhere.
Pro tip: Keep the pump in your personal moving-day bag alongside diapers and bottles, not in the truck, in case you need it on short notice during a long moving day.
Watch out: Do not pack a breast pump motor loose among heavier items, the internal motor and electronics are more delicate than the exterior suggests.