How important is oil in A/C compressors ?
Oil in the A/C system is essential, primarily to lubricate moving parts, i.e., the compressor. It also enables heat to travel and dissipate from the compressor. As with refrigerant, oil in the A/C system must keep its chemical stability.
Insufficient lubrication due to the wrong type of oil and viscosity is the second most frequent reason for A/C compressor damage and failure.
Distinct types of a/c oil like PAG,POE or mineral oils with a different viscosity do not mix, leading to poor lubrication, damaged seals and increased automotive air conditioning compressor wear
The use of the wrong type of oil could result in the hvac compressor’s piston rubbing against the cylinder surface. If the oil is too thick, it is unable to properly lubricate the tight space between the cylinder wall and the piston. Wrong oil viscosity can result in more internal friction, leading to an increase in compressor temperature and inevitably compressor damage.
Blending or mixing of diverse types of oils may result in a new different type and oil viscosity. This oil contamination build-up to the point where it can block the flow of refrigerant and oil, leading to poor lubrication and seizure of the compressor and major system failure.
Refrigerant moving oil and cooling down the A/C Compressor
it is extremely important that the engine not be run on a vehicle with a clutch less compressor if there is no refrigerant in the A/C system. This is because the compressor depends on refrigerant to carry lubricant inside of it.
How much oil should I add after a/c compressor replacement ?
After the refrigerant system has been charged and ran at the factory, the refrigerant oil in the A/C compressor is dispersed throughout the refrigerant system. The A/C receiver/drier, A/C evaporator, A/C condenser and the A/C compressor will each keep a significant amount of the needed refrigerant oil.
The refrigerant oil level in a new A/C compressor must first be adjusted prior to compressor installation.
Oil balancing the a/c system:
- Measure the oil recovered from the system by recovery/recycling/recharging station.
- Drain and measure the oil left in the old compressor using a beaker.
- Drain the new compressor and refill it with the same amount of oil removed from the system and old compressor .
- For Example :if 2 oz of oil are recovered from the system and 2 oz of oil was drained from the old a/c compressor, drain the new replacement a/c compressor and then add 4oz of the proper oil type and viscosity to the compressor before installation.
Installing the ac Compressor without balancing the oil in the system, gives a considerable risk of liquid lock, due to too much oil in the A/C system! When adding oil to the ac compressor in your car one out of two methods could be used and the right one will depend on the type of compressor. Oil could be added through the ac compressor oil service port or through the low side or intake of the compressor. Always add oil through the oil service port if it comes with one or compressor damage may result.
Most reclaim/recycling recharging stations will measure the lubricant being removed during recovery. This amount of lubricant should be added back into the system after the repairs are done.
How could the oil in my car’s A/C system be low?
Leaking automotive air conditioning systems will leak out refrigerant and the oil that resides inside of the compressor.
Refrigerant oil must be added when an A/C condenser, A/C receiver/drier or A/C evaporator is replaced
Refrigerant oil loss will be evident at the leak point by the presence of a wet, shiny surface around the leak.