Update your semi with a secure transfer of essential fluids, with the Dorman Heavy Duty Pressurized Coolant Reservoir that ensures you're Ready for the Road Ahead™. Due to robust tank that can hold pressurized coolant, this replacement component is able to aid in the chilling of the engine and radiator during vehicle operation. Constructed with a durable construction and secure cap to prevent fluid leaks. FleetPride is your First Click in Heavy Duty®.