What is an air conditioning service?
Air conditioning system service typically entails refilling your freon gas and repairing minor leaks, if detected.
When should service be performed?
A freon gas recharge is not usually required until the car has quite a few years or miles. Usually the need becomes apparent when the air blows hot from the vents. A fully charged system can reduce ambient temperature more than forty degrees fahrenheit. As the air conditioning system ages, freon may seep out through small leaks where parts are joined together and sealed with rubber o-rings (a circular gasket). When these o-rings begin to dry out, they can no longer provide an airtight seal. The system will still reduce cabin temperature even with half the required freon, but it will not be as effective. As your vehicle ages, a recharge of the system about every three years is normal.
What are the symptoms of faulty air conditioning?
If you have your freon gas recharged and start experiencing reduced performance within a short period of time, you may have a more significant leak that must be diagnosed and repaired. Usually, one of the condenser or evaporator lines has developed a hole where the freon leaks more rapidly. Another cause of air conditioning system failure is if a component has failed mechanically. The compressor is the most common failure item. The pulley on the compressor is in constant motion, even when the air conditioning system is not in use, and will wear out over time. The compressor also contains the most moving parts within the system, so breakdown at some point is expected. In newer cars with advanced climate control, sensor and computer problems are quite common. If a sensor stops working or if it measures incorrectly (either pressure or temperature) the system will stop working.
How air conditioning works?
Air conditioning provides passenger comfort when driving. Ambient temperatures and heat generated by the engine can create a very uncomfortable cabin for passengers. Air conditioning does not provide cold air, but instead removes heat from the air inside the cabin. The freon under high pressure will pass through a valve either called a thermal expansion valve or an orifice tube, which allows the freon to rapidly expand. This drop in pressure creates a drop in temperature. The freon then passes through tubes in a radiator-looking device inside the cabin called an evaporator core. The air inside the passenger cabin is pushed through this evaporator core before it exits the vents and has the heat taken out as the freon seeks to regain surrounding temperature. This process also takes all the humidity out of the air in the cabin (think of the evaporator core as a cold can of soda with condensation). This air drying process also makes defrosting windows in the winter much easier. The air conditioner will be active when defrost is commanded, even with the heat running. This takes moisture out of the air and speeds up window defrosting.
What can happen if this service is neglected?
Air conditioning system neglect can create problems. For the most part, a non-functioning air conditioner means no relief from high temperatures and humidity. And in colder climates, faulty air conditioning may increase the time required to defrost or defog windows before driving safely. In some cases, mechanical failure may lead to other problems with the vehicle. A seized AC compressor can break the serpentine belt and leave the car without a power steering pump, an alternator, and a water pump. Finally, freon is an ozone depleting agent, so any leak in the system is detrimental to the environment.
What does the typical air conditioning service cost?
- Estimated diagnostic + recharge cost: $100–$250
- Estimated repair cost (if minor leaks are detected): $200–$800
Most automotive service professionals can perform this service. Keep in mind, pricing will vary by location and your vehicle make and model. Save time and money by using Openbay to compare pricing and book an appointment with a service center in your area.
Service article written by an ASE Master Technician