Symptoms of a Bad A/C Drier and Other FAQ

The air conditioning (A/C) drier is one of the most important parts of your vehicle’s A/C system. Without it, moisture, dirt, and other debris will slowly clog your A/C until the entire system just shuts down one day. Because of this, it’s important to know when it’s time to replace your A/C drier.

But First: Do You Have an A/C Accumulator or Drier?

To begin with, you need to determine whether you have an accumulator or a drier because you won’t have both. If the system is equipped with an expansion valve, it will always have a drier. If it is a fixed orifice system, it’ll have an accumulator, which does the same job the drier does as well as “misting” oil into the refrigerant to lubricate the compressor.

To begin with, you need to determine whether you have an accumulator or a drier because you won’t have both. If the system is equipped with an expansion valve, it will always have a drier. If it is a fixed orifice system, it’ll have an accumulator.

–Richard McCuistian, ASE Certified Master Automobile Technician

The accumulator is always mounted between the evaporator and the compressor and will be a large tank-looking assembly usually back near the bulkhead on the passenger side of the engine compartment. If you can follow the large suction line (the one that gets cold when the A/C is operating) from the bulkhead to the compressor, you’ll find the accumulator in that line if it has one.

If your car doesn’t have an accumulator, it will have a drier, which is a much smaller canister-looking assembly either in the small liquid line between the condenser (the heat exchanger beside or in front of the radiator) and the bulkhead or it’ll be part of the condenser itself. This kind of condenser with the drier built in is known as a “subcooler” because it not only condenses the refrigerant and absorbs heat, it also greatly cools the liquid refrigerant in a separate part of the condenser unit.

What Are the Symptoms of a Faulty Air Conditioner Drier?

Your vehicle’s A/C system has several parts that can go bad over time, so diagnosing the source of the problem can certainly be hard. Luckily, there are a few signs you can watch for if you think your A/C drier is the issue:

Not Enough Cooling

If your drier is clogged or contaminated, then your A/C likely won’t be able to cool your cabin sufficiently. Debris inside the A/C system can clog the drier and cause the desiccant to mix with the refrigerant and lubricant. In some cases, a leak can also cause poor cooling because there isn’t enough refrigerant in the system anymore. Either way, you should replace your A/C drier as soon as possible if this happens.

Refrigerant Leak

A puddle of refrigerant underneath your vehicle might be a sign of a bad A/C drier. Note, however, that this happens rarely.

Rattling Sounds

Damaged or loose parts in your A/C receiver drier will most likely move and make noise.

What Is an Air Con Drier?

Not all vehicles have an air drier. However, on vehicles with a thermal expansion valve, you can find the A/C drier between the condenser outlet and the expansion valve inlet. The A/C drier, also known as the receiver, removes water (moisture) from the refrigerant gas.

What Does a Car A/C Drier Do?

Your vehicle’s A/C compressor is in charge of pumping the refrigerant into the condenser, where the refrigerant changes from gas to liquid. It’s the A/C drier’s job to make sure that moisture is removed from the system to prevent corrosion within the compressor. Your A/C drier also filters dust, debris, and other dirt. It also temporarily stores excess refrigerant when the A/C system doesn’t need too much.

Other A/C Drier FAQ

What Causes the Drier To Go Bad?

Like most parts of your vehicle, your A/C drier can wear out over time. At some point, it won’t be able to properly absorb moisture or filter the refrigerant anymore. This may be caused by using the wrong oil mixtures in the A/C system, corrosion in some parts of the A/C, or carbonized oil caused by overheating.

Repairing other parts of the A/C system can also cause the drier to go bad. The desiccant is a hygroscopic gel that quickly absorbs moisture from the air. Opening the system allows outside air to enter and saturate the desiccant, causing it to lose its ability to further absorb moisture.

What Happens if You Don’t Replace the Drier?

If any major A/C system repairs are done (replacing compressor, condenser, evaporator, etc.), the drier or accumulator should always be replaced. If, however, the A/C is still working the way it should, there is no need to change the drier.

When Should You Replace Your A/C Drier?

This can vary depending on your vehicle’s make and model, so it’s best to check your owner’s manual for more information.

How Much Does it Cost To Replace an A/C Drier?

The final price depends on several factors, such as your vehicle’s make, model, and the product brand. In general, expect to spend anywhere from $10 to $120.

Keep in mind that a faulty A/C drier can also lead to other parts of your A/C system malfunctioning, which can lead to a bigger repair bill. This is why it’s important to replace your A/C receiver drier as soon as necessary.