Performed a cooling inspection on a Trane 2TTB4060A1000AA 4-ton air conditioning system installed in 2004. Checked refrigerant charge by measuring subcooling and superheat values across the system. Subcooling was low at 6°F, indicating an undercharged system. Added 2 lbs of R-22 refrigerant to achieve 12°F subcooling per specifications. Cleaned condenser coils using Nu-Calgon CalClean coil cleaner. Replaced air filters with 20x25x1 MERV 8 pleated filters. Tested all electrical components, safety controls, and condensate drainage. Lubricated fan motors with Supco SPL synthetic lubricant. Verified proper cooling operation and recorded data in service report.