What does a Freon leak look like in a fridge?

Detecting a refrigerant (Freon) leak in a residential refrigerator involves observing specific physical and performance symptoms rather than seeing a standard liquid puddle, because residential refrigerants are pressurized gases that evaporate instantly upon escaping. However, a key visual indicator of a refrigerant leak is a greasy, oily residue or sticky film coating the copper tubing, brazed joints, or evaporator coils, because refrigerant circulates mixed with compressor oil. When a leak occurs, that oil escapes and leaves a distinct residue. Furthermore, a leaking sealed system will cause food to spoil as the fridge stops cooling entirely, while the compressor runs constantly. You can troubleshoot performance drop-offs easily with a thermometer. You can verify leak presence when professional halide torch or electronic sniffer tests confirm a low charge.