When and How to Recharge Your Vehicle’s AC

There’s an unfortunate possibility that at some point over the years, you may need to perform an AC recharge on your vehicle. Now, your vehicle’s AC system is a precise, airtight pressurized system that won’t function properly should any leaks form. This means a normal AC system won’t naturally lose any freon over time or due to temperature fluctuations, and so long as no leaks appear later on the AC system should never need a recharge. Over time and after hundreds and thousands of miles, however, small leaks may form in the system, causing you to see a drop in your car’s AC performance. This article will quickly cover how to tell your car needs an AC recharge and the steps you can follow to recharge your AC.

There are typically a few telltale signs that your AC system has likely developed a leak and needs attention. One of the first signs you’ll probably notice is a drop in your AC performance. In other words, you may notice that the AC isn’t as cold as it was the previous Summer when you blast it for the first time this year. Since your AC system uses freon to cool the air it blown into the cabin, losing some of your freon to a leak will prevent the system from being able to fully cool the air.

There are other ways to tell that your AC system needs attention besides a noticeable drop in AC performance. Although these symptoms may be easier to spot, they typically indicate a slightly more serious problem may have occurred in your AC system. While a slight leak and minor loss of freon may simply cause your AC to blow warmer air, a more severe problem may prevent the AC clutch from engaging. The AC clutch engages at high AC settings when the pressure builds in your AC system. You may have even noticed it before if you’ve ever heard a small clicking sound when you turn your AC on full blast. Because the AC clutch relies on a buildup in pressure to activate, a severe leak/loss of freon in your AC system can lead to decreased pressure, preventing the AC clutch from engaging at all, dropping your car’s AC performance on its highest settings.

Another very obvious sign of an AC system issue is any signs of freon leaks under your vehicle. Remember, your AC system is supposed to be a closed, pressurized system with no leaks at all. With that being said, if there’s enough freon leaking out of your vehicle to notice it while parked, it’s best you take your car in to be looked at by a professional immediately. In fact, because of the precise and delicate nature of your vehicle’s AC system, it’s best you leave any repairs it needs to a professional. In the meantime, if you suspect you may have a minor leak or have been noticing a drop in AC performance, let’s quickly go over the steps you can take to recharge your AC and fix the problem temporarily until you can have your vehicle looked at by someone else.

To start things off, pop the hood and start your car with the AC on its highest setting. Under the hood there’s an AC compressor which compresses the freon in your AC system, and the compressor runs off the accessory belt. If you see the belt and pulleys moving with the AC on high, the compressor is working and you’re probably just a little low on freon. If the parts aren’t moving, that means the compressor isn’t engaging. We’ll still add freon to the system as that will help us determine whether the compressor went bad, or if there simply isn’t enough freon to cause the compressor to engage.

After checking to see if the compressor is engaging, it’s time to take a quick pressure reading of the AC system before deciding whether or not freon should be added. To take the reading, start by turning off the vehicle and looking for the low-pressure service port. You can typically spot it by looking for a black or gray cap with an “L” on it. Using the quick-fitting end attach the hose from your pressure gauge to the low-pressure service port, being careful not to pull the trigger yet and add any freon. Restart the vehicle and watch the gauge; A normal AC system’s pressure should operate at 40psi. If your reading is under 40psi, you probably have a minor leak, which should be easily fixed by a recharge. If the reading is 0psi, however, you probably have a bigger problem that needs to be addressed by a professional; A recharge won’t be enough to fix things.

Now it’s time to attach the can of freon to your hose if it isn’t already. Make sure you use the right kind of freon for your vehicle and note there are a few exceptions to what normal vehicles use. If your car is from before 1994, it may have a system that uses R12 freon, which is no longer used in vehicles. If that’s the case, you’ll need to visit a professional to have the specialized system worked on. Another exception are hybrid vehicles; Many hybrid cars use different AC systems that aren’t designed for traditional freon and using normal freon to recharge the vehicle can cause costly damages to the vehicle.

Once you’re sure you have the correct type of freon attached to your hose, and the other end of the hose is still connected to the running car, you’re ready to add some freon. Holding the can upright, carefully pull the trigger in 5 or 10 second bursts to add freon to the system, then monitor the pressure gauge for changes. Remember, the goal is to get the pressure as close to 40psi as possible without overcharging the system. Since the AC system is a closed, pressurized circuit, you won’t be able to remove extra freon without spending extra time and money at a repair shop.

Once you’ve successfully added freon and your AC system is back to 40psi, carefully disconnect the freon and hose from the vehicle and store it in a stable, safe environment out of direct sunlight. It’s illegal to dispense freon into the atmosphere, and nobody wants to pollute the air we breathe. If your recharge kit came with a UV light, or if you have one at home, you can use it to check for leaks in your AC system. You may be able to save some money doing maintenance at home if the issue is simply a loose or bad hose. Either way, it’s best to take your car to a professional as soon as possible so that they can double check that there are no major issues and can make sure your AC system is fixed back to perfect shape.

If you’re looking to buy a recharge kit, or if you want a professional to diagnose and repair your AC system for you, Holbrook Auto Parts offers low everyday prices on everything you need to recharge your AC at home. Once your AC is charged up, our trained mechanics will take care of any issues in the system and get you back On the Move in no time!

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