a carton filling apparatus supplies precise quantities of a liquid food product , such as milk or fruit juice , into an open top container such as a thermoplastic coated paperboard carton . the carton filling apparatus includes a fill tank or reservoir which holds the liquid product and a vertical passage which has an inlet at its upper end communicating with the fill tank and an outlet at its lower end from which liquid is dispensed into the carton . a pumping chamber is connected to the vertical passage to draw a controlled quantity of liquid from the fill tank and then pump that liquid through the vertical passage to the outlet . a vertically oriented linear movable valve rod or stem extends along a vertical axis downward through the fill tank and the vertical passage . the valve stem has a first portion which permits liquid flow from the fill tank to the pumping chamber when the valve member is in a first position along the vertical axis and which blocks liquid flow to the pumping chamber when the valve stem is in a second position along the vertical axis . the valve stem also has a second portion which blocks liquid flow from the pumping chamber to the outlet when the valve stem is in the first position and which permits liquid flow from the pumping chamber to the outlet when the valve stem is in the second position . a valve actuator moves the valve stem along the vertical axis between the first and second positions . operation of the valve actuator is coordinated with operation of the drive for the pumping chamber .