A pump system has a base unit and a pump unit. The base unit includes an input part operatively connected to a driving source and a plurality of output parts to which power is transmitted from the input part. The base unit is capable of being mounted to a support member. The pump unit includes a plurality of pump shafts respectively driven by the plurality of output parts, a plurality of hydraulic pump bodies respectively driven by the plurality of pump shafts, and a plurality of pump cases for respectively surrounding the plurality of hydraulic pump bodies, the pump unit detachably connected to the base unit. The pump shafts are connected to the corresponding output parts by connecting the pump cases to the base unit.