Performed diagnostic on 4 year old system. Homeowner states that system Is not cooling as it should. It is not cooling the way that they remember it before. System was in cooling mode and running. Indoor temperature was 83, set point was set for 70. System was only producing a 9 degree temp split. Checked outdoor unit electrical and system components. All components are turning on and operating, but not cooling. Checked refrigerant levels and found system to be low on refrigerant, which is why it is not cooling correctly. Went over findings and recommendations with Leslie. With homeowner approval, went ahead and added 3 pounds of r410A refrigerant levels. Also added leak seal & dye. System is now producing a 20 degree temp split and cooling as it should. System is fully operational upon departure. Customer gave the OK to run card that was on file.