How do you put ac coolant in a car?

To add AC coolant to your car, first locate the low-pressure service port, typically found on the larger diameter AC line. Remove the cap and connect the refrigerant can's nozzle, following the instructions on the can. Start the engine and turn the AC to the maximum setting, then slowly release the coolant into the system until the desired pressure is reached. Always ensure you use the correct type of refrigerant specified for your vehicle.