When Should I Flush My A/C System

When Should I Flush My A/C System?

When was the last time you flushed your car’s A/C system? Many car owners are not sure when they need to flush their car’s A/C system. Professional mechanics advice that you should flush your system, when the A/C is opened for servicing. Another indicator that can help you know it is time to flush your car’s A/C is when you find a substantial amount of debris in your orifice tube. You can also inspect the refrigerant oil to check if you need to flush your system.

What Is A/C System Flushing?

It is not uncommon for an A/C system to be contaminated or suffer a failure. When servicing an A/C it is vital to restore the cooling performance and this is what is known as flushing. Flushing is done in order to clean out the system and remove all contaminants in it. Dirt causes problems and restrictions for a good function of a replaced compressor. It only takes a few particles of dirt to restrict the flow of oil and refrigerant in the A/C system.

When And Why You Need To Flush?

For a compressor to function properly, it needs to be lubricated at all times. The compressor needs oil to function because it is the only moving part in an A/C system. Oil also circulates through the entire A/C system which means that all other components have some oil coating as well. If dirt or debris gets into the system, all components get affected. Removing the oil from an A/C system is the only way to get rid of contaminants inside the system.

An A/C system needs to be flushed every time the compressor is being removed or replaced. Also, if there are any signs of contamination in the system, you should never hesitate to flush your A/C system. Make it a habit to inspect the orifice tube to check the condition of your A/C system.

Components In The System That Should Never Be Flushed

  • High side muffler assemblies
  • Accumulators and driers
  • Conventional and block type expansion valves
  • Compressor
  • Orifice tube

Components In Your System That Need To Be Flushed

  • A/C Condenser
  • A/C hose from the compressor to the condenser
  • Evaporator
  • High side liquid hose

Do I Need To Flush My Compressor Too While Flushing The A/C System?

Most A/C’s are flushed using the typical solvent flush methods. If this is the case with your system then you don’t need to flush your compressor in the process. The right way to flush a compressor is by removing it from the vehicle first and then drain the oil from it. Later, the suction port is filled with refrigerant and the compressor hub is then turned by hand to pump clean oil through it.


The information on this post has clearly shown why it is important to clean and flush a car’s A/C system. Do not forget that every system is different and therefore, you should be careful to follow the right procedure when flushing your car’s, A/C system. To prevent comebacks, add a layer of protection in the way of in-line filters. To check if you have completely gotten rid of all contaminants in your system after flushing, take readings using a pressure gauge to confirm.