Bad A/C Accumulator: Function, Symptoms, and Replacement Cost

Your vehicle’s accumulator plays an important role in recycling refrigerant. When the accumulator receives refrigerant from the evaporator, it prevents any liquid refrigerant from entering the A/C compressor, which isn’t designed for liquid intake. The accumulator also has a refrigerant reservoir, which is filled with excess refrigerant and a desiccant.

Accumulator Symptoms

The accumulator prevents moisture and debris from entering your vehicle’s A/C system. But after some time, the accumulator can corrode or clog due to foreign particles and moisture, which can lead to leaks. If this happens, then your vehicle might show the following symptoms:

Leaking Refrigerant

Vehicle air-conditioning systems made before 2021 use a refrigerant called R134a freon. This substance is extremely hazardous to the environment, as it’s 1,430 times more potent than CO2 as a greenhouse gas.

That being said, it is worth noting that the most significant greenhouse gas according to the EPA is water vapor, so the impact of R134 and CO2 can also be estimated in this context.

Accumulators don’t typically leak, but if they do, you’ll see refrigerant oil on or below the accumulator, but no refrigerant, because the refrigerant’s boiling point is about -22 degrees Fahrenheit. That’s what makes the refrigerant a refrigerant, because when a liquid boils, it absorbs heat and that’s what happens to the refrigerant in the evaporator.

When the A/C is turned on, the compressor compresses the refrigerant gas and sends it through the discharge line to the condenser, where airflow across the condenser tubes and fins draws heat out of the refrigerant so that it becomes a hot liquid.

That liquid refrigerant then leaves the condenser through the small liquid line under high pressure (200-300 psi) and is fed through an orifice tube into the evaporator where it becomes a low pressure liquid. The refrigerant then turns to a gas as the fan inside the car draws air through the evaporator’s fins and tubes, with the refrigerant absorbing heat from the air. This both dries the air and makes it very cold.

The refrigerant then leaves the evaporator and travels to the accumulator, where any remaining liquid is stored along with the refrigerant oil that readily mixes with the refrigerant. The accumulator also has a desiccant bag that absorbs any small amounts of moisture that might be in the refrigerant.

At the bottom of the U-shaped tube within the accumulator is a small hole with a screen where the oil and refrigerant are drawn by the compressor through the screen and into the tube. This is where the oil and refrigerant mix travels through the suction line (30-45 psi) to the compressor. The oil in the refrigerant lubricates the compressor, and the cycle is repeated.

Cooling Issues

If the accumulator is leaking, refrigerant will be lost and the A/C won’t cool as well.

Does a bad A/C accumulator cause a moldy odor?

The evaporator is located so that it shares the passenger compartment. Since it gets so cold while the refrigerant is absorbing heat, it gathers moisture on its outer surface like a cold can of soda pop. Sometimes, mold will grow on the outside of the evaporator and you can smell it.

Note that the accumulator has nothing to do with this. All the moisture being absorbed by the accumulator is in the sealed refrigerant system.

If you have a moldy smell like this coming out of your A/C register, you can turn the A/C on “norm” (not “max” or “recirc”) so that it’s getting air from outside. That air enters at the base of the windshield on the passenger side through the cowl vent near the wiper arms. If your vehicle has a cabin air filter, remove it for this next step.

With the A/C on high blow, drawing the maximum amount of air through the cowl vent across the evaporator, spray disinfectant into the cowl vent. The disinfectant spray will usually kill the mold and mildew that is causing the smell and will also tend to make the inside of the vehicle smell fresh in the process.

How Much Is a Replacement A/C Accumulator?

A/C accumulators can cost around $10 to $60, depending on factors like brand, size, and design.

If you plan to replace the accumulator yourself, make sure not to vent any refrigerant to the atmosphere. Always remember to wear gloves and safety glasses while working around refrigerant systems.

If you know for a fact that the A/C has already lost all of its refrigerant and is filled with atmosphere, you can replace the accumulator yourself, but the A/C system must be evacuated of air before recharging with refrigerant. If you don’t do this, the A/C compressor will most likely become an air compressor, and air doesn’t condense into a liquid like refrigerant does. Be careful not to make this mistake because it can result in potentially more expensive repairs.

Where to Get a New A/C Accumulator for Your Vehicle

Driving with a faulty A/C accumulator can be stressful because of the leaks and cooling issues that come with it. This makes for an uncomfortable ride, especially during the summer when the heat is at its peak. Luckily, CarParts.com has an array of accumulators for you to choose from, all at reasonable prices.

Our catalog features high-quality auto parts, all sourced from the most trusted manufacturers in the industry. This way, you can look forward to your replacement accumulator lasting as long as your vehicle’s lifespan.

The best part is that you can enjoy competitive pricing when you shop online. Get a new A/C accumulator for as low as $16.

We have distribution centers equipped with advanced technology to ensure fast and efficient shipping. Shop now, and get your order in a matter of days.

Order a new A/C accumulator at CarParts.com today!