SEQUENCE OF WORKS
1. Periodically check the coolant level in the expansion tank on a cold engine, since there is no pressure in the cooling system and the coolant is in normal condition.
2. The coolant level is clearly visible through the transparent expansion tank when the cap is closed. When the engine is cold, the level should be slightly above the lower mark.
When the engine is warm, the coolant expands and its level in the tank rises. Therefore, there must be enough space in the tank for the expanding liquid.
3. To top up, carefully open the expansion tank cap. When opening the expansion tank cap on a hot engine, be careful, as the escaping vapors can cause severe burns. To do this, cover the expansion tank cap with a thick layer of cloth and slowly unscrew it until a hissing sound is heard. After the hissing stops, slowly unscrew and remove the cap from the expansion tank. When opening the tank, watch for the formation of bubbles and the presence of oil suspension - these are signs of a faulty cylinder head gasket.
Do not fill the coolant above the mark, as when heated, the coolant expands and its excess is removed from the cooling system.
Fig. 6.4. Topping up the expansion tank with coolant (pre-mixed antifreeze and water in a certain proportion)
A small amount of coolant can be added both when the engine is hot and when it is cold (Fig. 6.4).