Performed preventative maintenance for 2 air conditioning systems side by side in the basement. Inspected all the electrical components. Confirmed proper high and low voltages. Customer recently replaced both air filters (2-16x25x1). Tested the amp draw of the blowers, compressors and fan motors. All were operating within the manufacturer specs. Tested the temperature split between the supply and return. The 1st floor system is operating at a 20° differential and the 2nd floor system is operating at a 10° differential. The second floor system has been having issues. 2 years ago we added refrigerant and it has leaked out. This time we are adding EZ Seal dye/sealant with 2lbs R410A refrigerant. System ended up with a temperature split of 20° on a 55° day with a subcooling of 9.7°. Customer would like to follow up at end of the season to make sure everything is ok or if the system needs a repair. Inspected the gravity drains to 2 separate condensate pumps.