No. Your car’s A/C refrigerant never goes bad. Nor do you “use up” the refrigerant that is in your system. If your vehicle’s A/C system pressure is low, your vehicle has a refrigerant leak and that leak will need to be repaired in order for your system to hold refrigerant. If your vehicle is able to maintain a charge for a period of two weeks or longer, then it is possible to seal the leak with sealant such as Super Seal. If your system will not hold a charge for at least a two week period then it is advisable to seek professional assistance to find and repair the leak.