An internal combustion engine needs good cooling. During operation, excess heat is discharged into the environment. To intensify this process, water is used as an intermediate heat carrier, which makes it possible to increase the cooling surface area and ensure reliable heat removal.
During normal operation of the motor, the level of antifreeze remains constant. A drop in the liquid level in the expansion tank indicates a malfunction. Most likely, antifreeze is poured onto the road through leaks in the engine cooling system. First of all, it is necessary to check the rubber pipes. As a result of exposure to high temperatures, accelerated aging of the material occurs. Cracks appear, through which antifreeze seeps drop by drop. Cracks may appear in places inaccessible for inspection. In this case, use a small mirror or touch the tube with your hands to detect them. Before carrying out any operations on the cooling system, the engine must be completely cool. Failure to do so may result in severe burns. Check the tightness of the clamps with which the rubber tubes are attached to the fittings. If there are no signs of leaks on visual inspection, the cause may be pump wear. When the resource of the stuffing box is depleted, antifreeze begins to flow along the pump rod. In this case, the escaping liquid is sprayed onto the surrounding objects perpendicular to the pump rotation axis. The pressure in the engine cooling system is higher than in the oil sump. If cracks occur in the metal of the cylinder block or if the head gaskets are destroyed, antifreeze can be squeezed into the oil channels. This is a serious malfunction that can seize the engine. Engine oil mixed with antifreeze forms an easily foaming emulsion. Its lubricating properties are low. The result is increased friction. It is quite easy to detect a leak in the oil sump. White foam will be visible on the dipstick, and overheating of the engine can also cause the antifreeze to disappear. As the temperature rises, it begins to boil, the pressure in the cooling system circuit rises. In this case, a safety valve is provided in the cover of the expansion tank. When the pressure is exceeded, it opens and discharges antifreeze vapors into the atmosphere. With a sharp drop in pressure, the antifreeze begins to boil, and the liquid phase can be thrown out along with the steam.
