Method for filling and evacuating a dispenser unit and filling insert for dispenser unit

A filling insert for a dispenser unit for a paste-like, foam-form or liquid medium, the dispenser unit including a storage container for the medium and a suction pump, arranged on the storage container in a pump mounting and sealing the storage container against air penetrating from the exterior, the suction pump being configured to deliver the medium in response to an actuating action, the filling insert comprising:

• at least one air duct connecting the interior of the storage container with the ambient environment during filling, and configured to be closed after evacuation, the at least one air duct being arranged outside a conveying path of the suction pump, wherein at a first pressure level, air can be evacuated from the storage container and at a second pressure level, medium penetrates into the air duct, wherein the first pressure level and the second pressure level are distinguishable from each other by the flow counterpressure, so that on or shortly after reaching the second pressure level this is detectable, so that the evacuation is terminated and the air duct can be closed;
• wherein the air duct is formed by a straight or curved duct, penetrating the wall of the suction pump;
• wherein the air duct being coupled to the pump mounting, the pump mounting having a duct section, and with a defined screw-on angle of the suction pump onto the pump mounting the two duct sections to an open duct are congruent with each other and by further turning of the suction pump the two duct sections are able to be moved away from each other to close the air duct;
• and
• wherein the air duct at least in one dimension has a width of less than 2.