The Coolant Reservoir Tank, also known as the Expansion tank or Overflow tank, is used as a storage area for excess coolant in the vehicle's cooling system. The coolant reservoir tank is connected to the cooling system by hoses. These hoses allow coolant to flow into and out of the tank as needed to maintain the proper coolant level in the system. It is typically made of plastic.Attributes:• Prevent overheating by providing a reservoir for excess coolant• Prevents corrosion and offers high ductile, impact strengthApplications:The Coolant Reservoir Tank is designed to prevent air from entering the cooling system by creating a closed system.