Abstract: A self priming pump system that includes a motor coupled to a centrifugal pump. A separator having a reservoir is provided for storing a limited amount of pumped fluid in advance of the centrifugal pump. A vacuum source provides a vacuum suction to the reservoir to draw pumped fluid into the reservoir to prime the pump. A float may be provided, wherein when the fluid level in the reservoir reaches a desired level, the float opens a float valve to let air into the reservoir to maintain the desired level. The float valve may have a capacity that is greater than or equal to the pumping capacity of the vacuum pump, or at least large enough to make up for a difference between the pumping capacity of the vacuum pump and an amount of fluid that can be pumped by the centrifugal pump from the reservoir.