Ultimate Cooling Tune-Up: cleaned coils, brushed and cleaned traps, added pan treatment tablets to pan. tested and checked all controls, wiring connections. tested temperatures, checked filters. checked refrigerant temperature and pressures, tested static duct pressure. tested blower operation, tested cooling operation to ensure working within manufacturer specifications. Second floor unit was low on refrigerant. Added 6 pounds of refrigerant. Performed a leak search. Found leak middle of evaporator coil on right side.