The hoses must not sit short on the fittings.
Check tightness of clamps. Use screw clamps whenever possible.
Check the expansion tank cap gasket for damage.
Caution: A low coolant level may be due to an improperly screwed cap.
Check the tightness of the radiator drain tank.
If the coolant level drops rapidly and no leaks are found, check the cooling system with the engine warm. To do this, warm up the engine and let it idle until the fan turns on. Check whether coolant is escaping in the area of the water pump.
A noticeable drop in the coolant level and/or oil in the coolant, as well as white smoke in the exhaust gases when the engine is hot, indicates a cylinder head gasket failure.
Caution: It is often quite difficult to locate a leak. Therefore, it is recommended to check the pressure cooling system with a special device in a workshop. At the same time, you can also check the safety valve in the cap of the expansion tank. Valve opening pressure: 1.2-1.4 bar.