Abstract: Disclosed is a cooling system comprising a cooling circuit with a deaeration device arranged in the cooling circuit for separation of air bubbles from coolant circulating therein. The deaeration device comprises a deaeration chamber having a coolant inlet connected to a feed pipe of the cooling circuit, a first coolant outlet connected to a coolant pump of the cooling circuit, and a second coolant outlet connected to an expansion tank via a static line. The deaeration chamber has a larger cross-sectional dimension than said feed pipe. The second coolant outlet is located in such a position in relation to the coolant inlet and the first coolant outlet that the coolant flow in the deaeration chamber between the coolant inlet and the first coolant outlet will move migrating air bubbles in the longitudinal direction of the deaeration chamber towards the second coolant outlet.

Abstract: A cooling system in a vehicle (1) powered by a combustion engine (2). A first line circuit (4) for cooling the combustion engine (2) and a second line circuit (5) which receives coolant from the first line circuit (4) for cooling at least one medium in a heat exchanger (14a, 14b). The second line circuit (5) includes a line (5b) with an extra radiator (9) and a bypass line (5c) with a valve (12) by which it is possible to distribute the coolant flow between the parallel lines (5b, 5c). A control unit (13) controls the valve (12) so that it leads at least a major part of the coolant through the line (5b) with the extra radiator (9) when there is need for extra cooling of the medium in the heat exchanger (14a, 14b) and so that it leads at least a major part of the coolant through the bypass line (5c) when there is no need for extra cooling of the medium in the heat exchanger (14a, 14b).