A fluid injector system includes at least one fluid reservoir having at least one interior surface and defining an internal volume, at least one actuator configured to change the internal volume of the at least one fluid reservoir, and at least one processor. The at least one processor may be programmed or configured to drive the actuator to at least partially fill the at least one fluid reservoir with a fluid from a fluid source, drive the actuator to generate a least a partial vacuum within the internal volume to dislodge one or more gas bubbles adhered to the at least one interior surface and to cause the one or more gas bubbles to coalesce into a coalesced bubble, and drive the actuator to expel the coalesced bubble from an outlet of the at least one fluid reservoir.