A reversible inflation system allowing a single pump to be used for both inflation and deflation of the air bladder. The present embodiment of the inflation system includes a motor and an impeller located within a housing having a diaphragm valve and a slide. Presently, the slide determines the direction of fluid flow through the housing, so that in a first position, the system causes fluid to flow into the bladder, and in a second position, the system causes fluid to flow out of the bladder.