Known Reasons for an A/C Compressor to fail with bonus installation tips

A Compressor can fail on its own, however in some cases a failed Compressor is caused because of an underlying issue. A few steps can dramatically reduce the chances of a failed compressor recurring. It is important to follow manufacturer’s installation procedures. In most circumstances failing to do so will void the manufacturer’s warranty. When working on A/C systems please follow all State and Federal legislation.

If your Compressor has failed, please check the following for possible causes before installing your new unit.

1. Has the A/C system had been undercharged or overcharged with refrigerant? An undercharged system will cause insufficient oil circulation throughout the A/C loop causing insufficient Compressor lubrication. Think of your A/C Compressor is the engine for your air conditioning, any engine will fail without adequate oil. Your A/C Compressor is no different. If the system has been overcharged with refrigerant this can cause excess pressure to 

Develop in the compressor, this excessive pressure can shorten a Compressors service life. This is rare on a factory fitted compressor but can occur when serviced by an unqualified persons. 

2. Excessive Refrigerant Oil Charge in system.  Excessive Refrigerant oil can cause “liquid slugging” inside the Compressor. This is very unlikely to have happened on a factory fitted compressor. Liquid slugging refers to a concentration of oil building up in the compressor and cannot pass through freely causing internal damage to occur. This is more likely to happen if oil has been injected directly into the low side charging port or directly into the compressor itself. It is always advisable to inject oil into the high side charging port only. If fitting a new Compressor attaching both A/C lines, rotate Clutch Hub a minimum 8-10 times to minimise any chance of liquid slugging upon initial start-up.) This will prevent the oil from being concentrated in one area and drastically reduce the chance of liquid slugging occurring. 

3.  When installing a Compressor  refer to the vehicle manufacturer’s specifications to determine correct oil type and charge rate. This can usually be found through the Vehicles service manual or a decal located under the bonnet. Using the wrong type or amount of compressor oil can drastically shorten a compressors life span. Compressors do come pre charged with oil although it is advisable to compare to vehicle manufacturers recommendations.

4. Contaminated oil. Compressors are high pressure pumps and have internal moving parts. When a Compressor wears over time it can create fine metal particles that mix in with the oil and flow throughout the A/C system. This in turn causes further Compressor wear.  This is the main cause of premature compressor failure. If upon removal it is found the Compressor oil is not clean the A/C system must be flushed with approved A/C flushing solvent to remove any contamination before fitting the new compressor or cross contamination will occur and damage to the new Compressor will likely result. All flushing solvent must be removed from the A/C system or allow enough length of time for the solvent to boil off under atmospheric pressure. Never flush through a TX Valve or Receiver/Drier. These must be removed prior to flushing. Parallel or Multi flow condensers cannot be flushed and must be replaced. Condensers cannot be flushed as flushing solvent will only follow the path of least restriction and will not clean the whole condenser. 

5. Air or moisture in the A/C system can be caused by poor service techniques. Moisture can cause a reaction to occur and the oil to develop into a sludge like substance. If the system is opened and exposed to the atmosphere for more than 15 minutes moisture will penetrate the A/C system and the Receiver/Drier must be replaced.

6. Although uncommon in all but older vehicles another known reason for a Compressor to fail is a term referred to as Black Death. Black death occurs when impurities are present within the air conditioning system due to a failed Receiver/Drier. These contain desiccant particles, over time this desiccant can break down and travel throughout the A/C System. Always replace Receiver/Drier when fitting a new Compressor.

7. Only Use New refrigerant your Compressor was designed for. In most cases this will be R134a on newer model vehicles it may be R1234yf. Do not use Minus 30 – HyChill or any other substitute refrigerant. This substitute refrigerant has not been approved by any Compressor manufacturer. Evacuate for a minimum of a minimum of 30 minutes before recharging with refrigerant.  

8. Check for loose Compressor bolts nuts, drive belts or mountings. 

9.  Make sure the Vehicle’s electrical system voltage is not below 9 volts. This is the minimum voltage needed for a clutch coil to operate correctly.