An actuation system particularly for vehicular use in which a pump (10b) draws fluid from a reservoir (10a) to supply one or more first consumers such as a steering valve (50). One or more second consumers such as a clutch actuator (12) are actuated via a solenoid valve (12a) from an accumulator (10c) charged by the pump. The solenoid valve connects the or each second consumer (12) to the accumulator or to the reservoir thus actuating the second consumers. At accumulator pressure levels below a predetermined charge level the flow of fluid to the or each first consumer (50) is restricted to a level sufficient to ensure effective operation of the or each first consumer whilst generating a back pressure sufficient to ensure charging of the accumulator. This flow restriction may be achieved by solenoid valve (12a) or by a separate charging valve (20).