What may happen if the alcohol evaporator in an air brake system is not kept filled?

Answer: B — Ice may form in the air storage tanks

If the alcohol evaporator in an air brake system is not kept filled, ice may form in the air storage tanks. This is because the function of the alcohol evaporator is to add alcohol to the air system to prevent moisture from freezing, particularly in cold weather conditions. When moisture present in the air storage tanks freezes, it can create blockages in the air brake system, leading to reduced brake performance or complete brake failure. Keeping the alcohol evaporator filled with the appropriate fluid helps to mitigate the risk of ice formation, ensuring that the air brake system operates effectively even in low temperatures.