Coolant Recovery Tank

The coolant recovery tank (also called the expansion bottle) holds excess coolant during the cooling system operation. As pressure and heat build up, the coolant expands and is then transferred to the recovery tank. This prevents fluid being lost during cooling system operation, while keeping the maximum amount of coolant in the system at all times. Another advantage of a coolant recovery tank is to keep outside air from being drawn into the engine block. Air, carrying outside contaminants, can cause corrosion to cooling system components.