Why Does Your Air Conditioning Need Recharging?

There perhaps is nothing more uncomfortable than being in a car on a hot summer day with warm air blowing out of the vents when the air-conditioning system is turned on. This could be occurring because the system is low on refrigerant and needs to be recharged or there is a leak somewhere. Let’s take a look at the ins and outs of recharging your car’s air conditioning.

Related: Common Heating and Air Conditioning Problems

Why an A/C Recharge Is Needed

What may need recharging in your car’s air-conditioning system is the refrigerant that circulates through the system to create cold air. This refrigerant — which at one time was referred to as “Freon,” a brand name — can be either a liquid or a gas, depending on where it is during certain phases of the cooling cycle. The refrigerant circulates in a closed system, meaning it never leaks out and doesn’t need to be added or serviced under normal circumstances. But if you’re asking this question, things are probably not normal.

There are several main components in your car’s air-conditioning system, including the compressor, condenser, evaporator, receiver-drier and expansion tube. All are connected to each other through tubes or hoses, and each of those connections have seals that can leak — as can the various components themselves. When a leak occurs, refrigerant escapes from the system, and your air conditioning no longer produces cold air. If enough refrigerant leaks out, the compressor won’t even turn on because the refrigerant contains lubricant that is needed to keep the compressor from seizing.

However, a very slow leak may not require any kind of repairs. In some cases, simply adding some refrigerant — sometimes referred to as “recharging” — will do the trick. Furthermore, some refrigerant contains a leak-sealing chemical that might solve the problem, at least for a while, which may mean recharging might not need to be done again for a year or more. Some may also have a brightly colored dye that will indicate where a leak is occurring, or you can buy cans of dedicated leak sealer. However, if the refrigerant leaks out quickly, there are relatively few places it can leak out that aren’t rather expensive to repair.

While it’s best to have any recharging and problem diagnosis done by a professional, there are products available that allow a person to try to recharge the system themselves. What’s needed is a can (or cans) of refrigerant and a charging hose, ideally with an inline gauge; some come together as one piece (can with hose attached), but you can usually reuse the charging hose and gauge on another can of refrigerant. 

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Recharging Your Car’s Air Conditioner

Do-it-yourself recharging kits are easy to find and aren’t very expensive — typically under $50 for a can of R-134a refrigerant with a hose and gauge attached, though you can also buy them separately. Make sure you know what kind of refrigerant is needed; the required refrigerant should be on an under-hood sticker. 

Although any recharging hose or kit should include instructions, they will be universal and not specific for your car. This is where Google can be your friend: Searching for “Recharging the air conditioning on a (year/make/model)” will likely bring up some handy websites or videos that can make things a lot easier — or at least, easier to follow.

Different Types of Refrigerant

In recent years, there have been at least three types of refrigerant in use. Typically, you can’t substitute one for another, at least not without some modifications.

Until the mid-1990s, cars commonly used R-12, which stopped being produced as it was determined to harm the ozone layer. You may still be able to buy R-12, either in an original container or one that has been reclaimed from an old car, or you can convert your car to use R-134a, which is what followed it. However, this conversion is usually complicated and rather expensive, and oftentimes, the air it produces doesn’t come out cold. R-134a was mandated starting with the 1995 model year, but many cars switched over a year earlier, and some sources indicate it may have been used in a few cars as early as the 1992 model year.

For the 2021 model year, regulations took effect that required manufacturers to use something other than R-134a — which likewise was determined to be environmentally damaging but has not yet been banned — and some carmakers had changed over well before then. While the replacement isn’t specified and only has to meet certain requirements, it appears that perhaps the most common refrigerant today is called R-1234yf.

If your car is between the 1995 and 2020 model years, it’s probably going to use R-134a, but there are exceptions at both ends of that range. If you have any doubt, check the sticker under the hood to confirm the required refrigerant.

One note: R-134a refrigerant originally came in a can that had a seal on top that was pierced when connected to a charging hose; if you removed the hose, the refrigerant leaked out (as it could over time even if the hose remained connected). But starting in 2018, in part because of its detrimental environmental impact, R-134a was required to come in a self-sealing can, which could be disconnected from the hose and still not leak out.

If you have a charging hose made for the early cans, which pierces the top of the can, it won’t work on the newer self-sealing cans. However, some manufacturers of hoses made for the newer self-sealing cans claim they will also work on the older “pierce-type” cans if you get a special adapter.

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