Air-conditioned car repair: what you need to know

This week we got our first taste of spring-summer weather. When you switch your car's HVAC settings from "heating" to "air conditioning", you may end up with a broken car air conditioning system. It's important to get your air conditioner back on before the summer heat hits. What can you do if your car's air conditioning system is not working properly? Here's everything you need to know about car air conditioning maintenance. 

How Automotive AC Systems Work

Before sorting through common problems and repairs, it's helpful to understand how your car's air conditioning system works. Unlike an oil change, you don't need to change or refill your car's A/C freon. While small amounts of freon can naturally be lost over time, your air conditioner is a sealed system designed to keep the freon recirculated—often for the life of your car. Freon circulation is possible due to the high internal pressure in this system. 

Here is a general overview of how your AC system works:

• Compressor-First, as the name suggests, your compressor compresses your freon before pumping it into the condenser. 
• Dryer-Cold air "holds" less water than warm air. As the air cools, it can begin to produce additional moisture. From the condenser, the air enters the dryer. As the name suggests, this component dehumidifies the air by removing excess moisture. It also contains a filter to help trap and remove debris. 
• Evaporator-Air is then supplied to the evaporator either through an expansion valve or through an orifice tube. This is where the cold air expands before being forced into your cabin by the fan.

Why refrigerant leaks are more than just refrigerant leaks

Unfortunately, refrigerant leaks mean a bigger problem in your car's air conditioner. A refrigerant leak means your sealed system is no longer sealed. This creates several problems:

• Obviously, a freon leak will not allow your car to hold on to the refrigerant. In order for your AC system to work, you need to find and repair the leak at the source.
• Because these systems are sealed, they are not designed to withstand external moisture, debris, or atmospheric pressure. Exposure can compromise your vehicle's entire AC system. 
• Your car's air conditioning system uses pressure to circulate oil and freon. It will automatically turn off when the pressure drops, which is a common side effect of freon leaks.

What causes an air conditioner refrigerant leak?

When an air compressor fails, its fan blades can scatter small pieces of metal throughout the system. Doing so may damage several parts of the air conditioner and cause refrigerant leakage. Refrigerant leaks can also be caused by a broken seal, broken gasket, or any other component in your system. Your Freon flows through your entire cooling system, making any part a potential leak culprit. 

How mechanics find leaks

When you take your car to a professional A/C mechanic, how do they find and fix leaks? 

This is a unique process that requires performance testing and recharging of the A/C system. Your mechanic will first inject freon into the system, but the freon is invisible, making pressure loss difficult to track. This way, your mechanic will also inject a dye into your car's A/C system, which will make the freon move visible under ultraviolet light. 

Then you may have to drive your car for a week or two and return it to a mechanic for inspection. This will give the freon enough time to travel through the system and identify all sources of pressure loss. 

Other potential car air conditioning problems

As we found out above, your car's AC system depends on several different parts to keep it running. A problem with any of these parts can disrupt your air conditioner. You may have a failed compressor, evaporator, dryer, or bad accessories (hose, seal, etc.). 

In addition, in many do-it-yourself air conditioner repairs, problems arise due to the fact that the wrong type of freon was used to refuel the system. As with oil, different cars require different types of freon. Unfortunately, as you now know, one faulty component can compromise and damage the entire system. 

Your mechanic will be able to assess the damage and help you find a repair plan, no matter what the source of your air conditioning problems is. 

Chapel Hill Tires | Local AC Car Repair Services

As members of your community, the local mechanics at Chapel Hill Tire know how important air conditioning is in the South. We are here to fix all your vehicle's air conditioning system problems. Chapel Hill Tire proudly serves the community through our nine offices in the Triangle area between Raleigh, Durham, Chapel Hill, Apex and Carrborough. We also typically serve drivers from nearby cities such as Nightdale, Wake Forest, Garner, Pittsboro and more. Book an appointment here online to get started today!

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