Air Con Compressor Oil Balancing

Oil balancing is a critical process when replacing Automotive Air Conditioning Compressors.

When installing a new air conditioning compressor on a vehicle it is important to make sure the compressor oil is balanced correctly with the correct type of lubricant and quantity.

The purpose of oil balancing is to ensure the amount of oil in the air conditioning system remains the same as per the original specification.

Without balancing the oil, the system gives a high risk of liquid slugging and compressor lockup, due to excessive oil, resulting in possibly further repairs.

 

1. Recovery of refrigerant

It is essential the oil removed from the system at the time of recovery is measured precisely. The same recovered oil quantity will need to be replaced in the air conditioning system.

 

This is an example of removing oil from an Air Conditioning Compressor:
tips-tricks-compressor-oil-balancing-1.jpg

 

2. Old compressor

Drain the oil from the compressor and measure the amount (volume). If necessary check the compressor installation guide for the appropriate oil drain procedure.

As a guide between 30-50% of the total oil quantity should be drained for a correctly operating air conditioning system.

Oil clarity is another good indication of system integrity. The image (right) of dirty compressor oil suggests there may be another fault within the air conditioning system, compromising original compressor performance.

 
This is what dirty contaminated Compressor Oil can look like:
tips-tricks-compressor-oil-balancing-2.jpg

 

3. The balancing act

Total amount of oil in the NEW compressor (A) is 120cc.

Oil amount drained from the OLD compressor (B) is 50cc.

(A) minus (B), 120cc -50cc = 70cc.

70cc is the required quantity that must be removed from NEW compressor (A) to maintain the correct oil balance.