A hydraulically-actuated system (10) includes a fixed displacement pump (16) with a plurality of parallel disposed pistons (32) that reciprocate in a pump housing (30) that defines a high pressure area (40) and a low pressure area (36). A control valve (17) is attached to the pump housing (30) and moveable between a first position in which the pistons (32) displace fluid in a first proportion between the high pressure area (40) and the low pressure area (36), and a second position in which the pistons (32) displace fluid in a second proportion between the high pressure area (40) and the low pressure area (36). A high pressure common rail (12) is connected to the high pressure area (40) of the pump (16). At least one hydraulically-actuated device (13) is connected to the high pressure rail (12). A source of low pressure fluid (14) is connected to the low pressure area (36) of the pump (16). An electronic control module (15) is in communication with and capable of controlling the position of the control valve (17).