What maintenance action is crucial for preventing compressor failure?

Regularly checking and changing the oil is essential for preventing compressor failure because the compressor relies on proper lubrication to function efficiently. Oil serves several critical roles in the compressor: it reduces friction between moving parts, helps to dissipate heat, and seals the gaps between components. Over time, oil can break down, deplete in additives, or get contaminated with debris and moisture, which can lead to increased wear and tear on the compressor. If the oil is not regularly checked and replaced as needed, it can result in overheating, increased friction, and ultimately, mechanical failure of the compressor.

In contrast, maintaining proper refrigerant levels, though important, typically addresses issues related to efficiency and cooling capacity rather than direct mechanical failure of the compressor itself. Cleaning the exterior of the unit is part of general maintenance but does not have a direct impact on the internal workings of the compressor. Monitoring ambient temperature is useful for understanding operational conditions but does not prevent compressor failure on its own. Thus, ensuring proper oil maintenance is the most critical action to keep the compressor running reliably.