Refrigerant gas leaks in air conditioners and refrigerators reduce cooling performance gradually rather than causing an immediate breakdown, which is why they often go unnoticed until the unit is running noticeably warmer than before. Common leak points include brazed joints in the copper piping, the flare connections at the service valves, and pinhole corrosion in the evaporator or condenser coil caused by prolonged exposure to moisture or corrosive air.
A technician typically locates a leak using an electronic leak detector, a soap bubble test at suspected joints, or by adding a small amount of UV-reactive dye that shows under ultraviolet light at the leak site. Once found, the repair involves either re-brazing the joint, replacing the affected coil section, or tightening and resealing a flare fitting, followed by a pressure test to confirm the repair holds before recharging refrigerant.
Simply topping up refrigerant without fixing the underlying leak is a temporary measure at best, since the same amount will leak out again over time, and repeated undercharging accelerates compressor wear. Refrigerant type also matters for the repair approach, since older R22 systems and newer R32 or R410A systems have different pressure characteristics and handling requirements.