Car AC Expansion Valve working Principle and Replacement Cost


Every vehicle has an air conditioner in it. If you live in a hot region of the world, then your driving comfort will depend on having a fully functional air conditioning system. There are so many vital components of the air conditioning system which make it work its magic. One important part is the AC expansion valve, which helps cause the liquid refrigerant to expand by removing pressure from it. Once it goes into the evaporator, the liquid gets converted into cool vapor. This is what produces the cool air that comes out of the air vents.

Basic Function and Working Principle

Another function of the AC expansion valve is to manage the flow of the liquid refrigerant. It manages this flow with the rod which exists inside of it. The rod can be moved either down or up, causing the passageway for the refrigerant to be either closed or opened; respectively. If the passageway is opened, the refrigerant will be able to flow through. If it is closed, the refrigerant cannot flow through. When you set the air conditioner to a higher temperature, this causes more refrigerant to flow through the passageway. That is how the air is able to get colder.

When the flow of refrigerant is regulated, it is basically metered by the AC expansion valve. In other words, the valve is calculating how much refrigerant must flow through the passageway based on the demands being placed onto it. This not only includes when the driver sets a colder temperature, but also when the temperatures outside are naturally hotter. Anytime the heat resistance is greater in the surrounding environment, the air conditioner will need even more refrigerant to create a cool temperature in the cabin.

Read also: 5 Causes of Oil to Leak into the Spark Plugs Tubes

Replacement Cost

You will notice when the AC expansion valve goes bad because your air conditioning system will ultimately stop functioning properly. It will either produce less cool air or it won’t produce any cool air at all. At this point, you will need to replace your AC expansion valve to fix the problem.

The replacement cost of an AC expansion valve is anywhere from $200 to $450. The parts cost itself will be between $100 and $200 while the labor costs will be between $100 and $300. There are also local taxes and other fees added on as well. If you want to reduce your expenses as much as possible, you should request quotes from the different auto shops in your area and see which one will give you the cheapest quote.


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