An air-operated double diaphragm pump, wherein the pump (40) is disposed with a shaft (30) and a bushing (28). The shaft (30) includes a plurality of indentations which allow passage of air and the bushing (28) is adapted to receive the shaft (30) and be in sliding engagement with the shaft (30). The bushing (28) includes vents (22) formed on the bushing and a hole (24) formed at each respective terminal portion of the bushing (28) to allow passage of air. The bushing (28) also includes ribs (26) protruding radially outwards from inner surface of the bushing (28) toward the shaft (30). The indentations (34) disposed along the shaft (30) and hole (24) formed at each terminal portion of the bushing (28) are alignable to create a path for air to travel.