7401 St. Louis Ave. Skokie, IL 60076

(847) 673-7930


Mon-Fri: 8:00 am – 5:00 pm

7401 St. Louis Ave. Skokie, IL 60076

Auto A/C Repairs

Car Air Conditioning Service

How Automotive Air Conditioning Systems Work

A/C systems may seem simple from the outside, but creating cool air to keep your car pleasant and comfortable is a fairly complicated process.

Let’s begin,

First you need a sealed system with a gas inside. The gas used is called refrigerant.  In older vehicles R12, and from the 90’s to now, R134a and R1234YF are used in automobiles. You probably heard the name “Freon.”

With your vehicles engine running when you turn on your air conditioning the A/c compressor engages and compresses the system’s refrigerant (Freon) sending it through a series of tubes and hoses while raising its temperature. As the Freon flows its next stop is through the condenser which is usually located in the grille of the car and in front of the radiator. The refrigerant enters the dryer, where it loses heat and moisture, and then pressure through an expansion device. The refrigerant then flows to the evaporator, which gets cold as the temperature of the Freon drops even further. The ventilation system then blows air over the cold evaporator, pushes cool air through a series of ducts and “doors” and finally into the passenger compartment through the vents. After all of this, its journey starts all over again. Just like that, you receive the relief of cold air

Signs of a Broken A/C System

Your car’s A/C system is one of the vehicle components that often becomes worn and damaged due to frequent usage and aging. When your vehicle’s air conditioning fails to provide the right temperature that you need, it’s important to have it checked, serviced, and repaired. Some common signs of a broken or malfunctioning air conditioning system include weak airflow, the air losing its cool, an unusual or rattling noise, leaking refrigerant, or a bad or unusual odor coming through the vents when the A/C is on.

If you notice any of these symptoms, contact McKenna Automotive Services.

A/C System Recharge

Sometimes, if your air conditioning begins to lose power and blows air that isn’t quite cold enough, it might just need a system recharge.

An A/C system recharge simply means evacuating, recovering and recycling any air or refrigerant in the system and then adding or “charging” the proper amount of refrigerant to allow the air to start blowing cold again.

However, it’s important to note that needing an A/C recharge is indicative of a larger problem. Your car’s air conditioning is a closed system and should not be losing refrigerant, so if you need an A/C recharge, it means you have a leak that needs to be repaired.

The problem is, Freon is a colorless gas, so most of the time you can’t tell where it’s leaking out from. To get around this, when we do a recharge at McKenna Automotive Services, we add a dye to the new Freon that we are introducing to the system. The dye stains the part that it leaks out from, allowing us to find the location of the leak and repair it.

Keeping your A/C working at its best is important to your comfort in the summer but also a safety item during the winter. In the winter, the windshield defroster uses air conditioning to remove moisture or fog from your windshield.

Routine inspections can keep your A/c unit from developing bigger problems, so it’s a good idea to ask for an A/C service when you have your oil changed and your tires rotated.

We’ll have your car feeling cool again in no time!

What our customers are saying:


I work for a business that is a block away from McKenna Automotive and they have been extremely helpful with getting our lift working as well getting work done on my personal vehicle. Their pricing is very competitive and worth every penny.