Abstract: The radiator tank comprises a deflection chamber (2) comprising a top wall (3); a bottom wall (4) having a water outflow hole (9); an air inlet hole (10); and an air outlet hole (11). Inside the deflection chamber (2) a deflection element (12) is arranged, by which air charged with water droplets and flowing in through the air inlet opening (10) is deflected. The air inlet opening (10) is arranged in the top wall (3) and/or in a front wall (5) and the air outlet opening (11) is arranged in the top wall (3) and/or in a rear wall (6). A flow hole (15) is arranged between at least one side wall (7, 8) of the deflection chamber (2) and a side edge (36) of the deflection element (12). Near said flow hole (15) at least one guide structure (53) is provided to guide air flowing through the deflection chamber (2) around the side edge (36) of the deflection element (12).