Performed tuneup on 2 AC systems. Inspected indoor and outdoor coils, flushed drain line, replaced air filter, inspected blower wheels, checked temperatures, checked static pressure, checked refrigerant pressures, inspected all major in minor electrical components. Upstairs system not cooling properly, found system low on refrigerant. Client approved to put UV dye into system and charged with 3 pounds of refrigerant. Need to return in 3 to 5 days to perform leak search with black light. Both systems are up and running and cooling good at this time.