Effects of Refrigerant Loss to the AC System
The components of the AC system can function properly only if they are lubricated regularly. In addition to keeping the system lubricated, the oil cools the compressor down. Therefore, when the oil level drops, it also means less cooling for the compressor. The lower the oil level drops, the more damage can be sustained by the AC parts. When the operating temperature raises, the chances of internal damage also increases.
The oil will show signs of corruption before a failure occurs and if these signs are recognized soon enough, the problem can be identified and rectified at the earliest. The oil should be clear when it is being used in the system. As the amount of oil in the system lowers, the heat rises and begins to burn the oil. The burnt oil will get darker and darker as the damage increases.
The refrigerant evaporates at a lower temperature and condenses at a higher pressure. Loss of the refrigerant usually occurs due to leaks in the hoses or other components of the AC system. As each ounce of refrigerant is lost, the compressor runs hotter and hotter. Finding the leaky spot in the system is the very first step to prevent refrigerant loss. Once the source of the leak has been identified and the old oil swapped for new, future problems may be averted.
The photos below are examples of the effects of refrigerant loss/overheating on the internal components of the AC compressor.
Oil after extended use should be clear. In this particular example, the compressor had 150,000 miles when removed. As long as the system is operating normally, has a full refrigerant charge and is free of contamination, no oil degradation will occur.
This example is from a compressor exposed to either partial loss of charge or high discharge pressures. Once the cause of high temperature is corrected the compressor and system should function normally.
Black oil results from extreme compressor overheating due to loss of refrigerant charge. Normally contamination in the form of metal bits will be found in black oil and it is critical that the system be flushed before installing the new compressor.
Disclaimer: This is not an official install or instructional guide and BuyAutoParts.com is not responsible for any damage or injury that can occur during these procedures.
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