When inspecting a hermetic system known to be leaking, what should you primarily look for?

In a hermetic system that is known to be leaking, the primary indicator to look for is traces of oil. This is because refrigerants often contain oil that is necessary for the lubrication of the compressor. When a leak occurs, the refrigerant escapes, and as it exits, it typically carries some oil with it. Therefore, finding oil deposits around the system's components can indicate the location of the leak.

Oil traces can accumulate near joints, fittings, or any points of vulnerability, providing a clear visual cue to technicians. This is particularly important in a hermetic system, where the refrigerant is contained, and the presence of oil signifies that both refrigerant and lubricant have escaped from the system due to a breach.

While frost on the tubing can indicate low refrigerant levels due to a leak, it is not an absolute sign of the leak's location. Puddles of refrigerant can also result from leaks, but refrigerant gases can evaporate, leaving little trace on their own. Particles of the filter drier core suggest other system issues but do not directly indicate the presence or location of a leak. Therefore, searching for traces of oil is the most effective method to pinpoint a leak in a hermetic system.