Abstract: The invention concerns a cooling system, in particular a motor vehicle cooling system comprising a cooling circuit, in which a cooling medium is circulated by means of a cooling medium pump; wherein the cooling medium pump or another work machine is driven by means of a drive machine via a hydrodynamic coupling, comprising a pump impeller driven by the drive machine and a turbine wheel driving the cooling medium pump, which together form a toroidal working chamber which can optionally be filled with working medium; wherein the working medium is the cooling medium; a compensating container, comprising a space filled with cooling medium and an air chamber above a cooling medium level in the space filled with cooling medium. The invention is characterised in that the working chamber of the hydrodynamic coupling is always connected to the air chamber or can optionally be connected to the latter via an air-conducting connection.