An actuation system (3;3') comprising: a pump assembly (11;71) including a pump chamber; an actuator having first and second chambers (44,45) and a movable member and configured to convert pressures applied to said first and second chambers (44,45) into a movement of said movable member; a valve section (12,13;72); and a controller (7;7') configured to control said valve section (12,13;72) to: open a first flow path (21,22;81,82) between said pump chamber and said first chamber and close a second flow path (21,23;81,83) between said pump chamber and said second chamber, during a discharge period (53;93) during which said pump chamber is pressurized, in a first mode; close said first flow path (21,22;81,82) and open said second flow path (21,23;81,83) during an intake period (54;94) during which said pump chamber is depressurized, in the first mode; close said first flow path (21,22;81,82) and open said second flow path (21,23;81,83) during the discharge period (53;93) in a second mode; and open said first flow path (21,22;81,82) and close said second flow path (21,23;81,83) during the intake period (54;94) in the second mode, wherein, when said first flow path (21,22;81,82) and said second flow path (21,23;81,83) are opened, they are opened after a predetermined time from the time when the discharge period (53;93) or intake period (54;94) starts, and when said first flow path (21,22;81,82) and said second flow path (21,23;81,83) are closed, they are closed before the discharge period (53;93) or intake period (54;94) ends. a pump assembly (11;71) including a pump chamber; an actuator having first and second chambers (44,45) and a movable member and configured to convert pressures applied to said first and second chambers (44,45) into a movement of said movable member; a valve section (12,13;72); and a controller (7;7') configured to control said valve section (12,13;72) to: open a first flow path (21,22;81,82) between said pump chamber and said first chamber and close a second flow path (21,23;81,83) between said pump chamber and said second chamber, during a discharge period (53;93) during which said pump chamber is pressurized, in a first mode; close said first flow path (21,22;81,82) and open said second flow path (21,23;81,83) during an intake period (54;94) during which said pump chamber is depressurized, in the first mode; close said first flow path (21,22;81,82) and open said second flow path (21,23;81,83) during the discharge period (53;93) in a second mode; and open said first flow path (21,22;81,82) and close said second flow path (21,23;81,83) during the intake period (54;94) in the second mode, open a first flow path (21,22;81,82) between said pump chamber and said first chamber and close a second flow path (21,23;81,83) between said pump chamber and said second chamber, during a discharge period (53;93) during which said pump chamber is pressurized, in a first mode; close said first flow path (21,22;81,82) and open said second flow path (21,23;81,83) during an intake period (54;94) during which said pump chamber is depressurized, in the first mode; close said first flow path (21,22;81,82) and open said second flow path (21,23;81,83) during the discharge period (53;93) in a second mode; and open said first flow path (21,22;81,82) and close said second flow path (21,23;81,83) during the intake period (54;94) in the second mode,