Ensure your semi truck is Ready for the Road Ahead™ with reliable AC, with the National R134a Refrigerant. To optimize the performance of an AC system, this replacement fluid absorbs heat from the air inside of a vehicle, allowing a system to blow cold air to the best of its abilities. Poor-quality refrigerant that needs to be filtered or changed shows signs such as warm air, grinding sounds, or frost on AC components. FleetPride is your First Click in Heavy Duty®.