The cooling system works under pressure. The radiator cover has the built in spring which is picked up in such a manner that the cover lining closes a contour of system of cooling and opens it if pressure in cooling system rises to 1,4 1,8 bar [140—180 кПа]. Pressure in cooling system raises because of expansion of a cooling liquid that leads to boiling rise in temperature.

For check of a cover of a radiator it is used радиаторный the pump. The work order is similar described for the petrol engine. With the help радиаторного the pump it is possible to check up cooling system on presence in it of places of leaks of a cooling liquid.