Perfomed annual AC precision tune up. Clean and tune up AC; cleaned condenser coil, checked all outdoor electrical components, tested indoor air flow, checked refrigerant levels, and tested overall AC operation. System was low on refigerant. Informed customer this will cause no cooling issues in the future. Charged system with R-410 refigerant to within the manufacture specified levels. System now cooling properly and efficiently. Also added a leak sealant to attempt at sealing leak. This is bandaid repair and may not always hold leak. If problem persists, a leak search of the system would be needed, or installation of a new condensing unit.