Abstract: A pump assembly for pumping a fluid lubricant such as grease or oil, the pump assembly comprising: a pump mechanism configured for moving a fluid lubricant; a pneumatic cylinder configured for being powered by an air source, the pneumatic cylinder comprising: a movable member for operating the pump mechanism, wherein the pump assembly further comprises a switch for detecting a position of the movable member; a valve configured for shifting a position of the moveable member upon an activation of the valve; and a control unit operable connected to the switch and the valve. The control unit is configured for controlling the activation of the valve in response to a detection of the position of the movable member by the switch, such that a pumping effect of the pump mechanism can be controlled. The pump assembly can be integrated into a lubrication system.