Things to Know First before Buying a Desiccant Bag
Probably one of the most ignored components inside your car’s A/C system, the desiccant bag—despite its small size—plays a big role in keeping the A/C in top shape. This component is found inside an A/C drier or accumulator and is used to absorb excess moisture from the refrigerant and trap debris. Once this moisture-absorbing component fails, excess moisture inside the A/C system can react with the refrigerant and create an acid-like substance that will damage the o-rings and seals. This is why whenever the desiccant bag is exposed to external humidity, it has to be replaced as soon as possible. To make sure that the replacement you get is the right one for your ride, here are some things you need to know first:
Your car either has a receiver-drier or accumulator.
Depending on your car make and model, your vehicle’s A/C system either uses an accumulator or receiver-drier. These devices look the same on the outside but they have slightly different functions. An accumulator is designed to catch and trap excess refrigerant dripping from the evaporator to keep the compressor from getting contaminated. It also contains a desiccant and strainer to clean and purify the refrigerant. The receiver-drier, on the other hand, is designed to store refrigerant and ensure a constant supply for the expansion valve. But just like the accumulator, it also contains a desiccant to absorb moisture and keep the refrigerant free from debris. So before you purchase a replacement desiccant bag, make sure first that it suits the specs of your vehicle’s accumulator or receiver-drier.
A desiccant bag also comes in a kit.
To make the most out of your budget, opt for a desiccant bag kit. This kit usually includes the actual desiccant bag, a plastic insert with filter, and the snap and header ring. You may be able to buy these components separately, but it’s best to buy them all in one kit since you’re sure that the filters and ring will perfectly match the desiccant bag’s specs.
Not all moisture-absorbing bags are created equal.
Desiccant bags may all look the same, but some are designed to perform better than others. A good choice is one that’s made of compact polyester felt and is reinforced with a unique sealing technology to prevent leaks.
Car Care 101: Replacing the Desiccant Bag
Without a functioning desiccant bag, excess moisture inside your car’s AC system will mix with the refrigerant and result into a corrosive acid that can eat through the gaskets and seals. This is why it’s important to replace a faulty or old desiccant bag as soon as you can. Now you don’t have to bring your ride to the shop or hire a mechanic to install one. As a matter of fact, you can replace this component within the comforts of your garage as long as you have basic repair knowledge and the right tools. Here’s what you have to do (Instructions are for a 1976 Firebird Trans Am with a VIR or EEVIR assembly):
Difficulty level: Easy
- Cloth or rag
- Refrigerant oil
Step 1: Discharge the system. Since you will be dealing with your vehicle’s AC system, you’ll have to discharge it first. However, this maintenance routine should be done by an EPA-certified mechanic because it involves the removal of Freon or the refrigerant, a toxic chemical that shouldn’t be released into the environment without the right tools.
Step 2: Clean the AC’s receiver shell. Using a clean cloth or rag, wipe away dirt from the receiver shell’s outside part.
Step 3: Remove the receiver shell. Using a screwdriver, remove the screws that attach the receiver shell to the assembly. Then pry off the mounting bracket clamp from the bracket. Get a good grip on the housing and nudge the lower end of the receiver to puncture the seal. Once the seal is broken, you’ll be able to get access inside the receiver and remove the old desiccant.
Step 4: Place the new desiccant bag inside the receiver. Add a bit of fresh refrigerant oil. Then install the new O-ring seal that usually comes with the desiccant kit. Make sure to coat the new seal with refrigerant oil to help keep it in top shape for many years.
Step 5: Reinstall the receiver shell. Once you’ve placed the new moisture-absorbing bag inside, reattach the receiver shell by screwing it back in place. Make sure to torque the screws according to the manufacturer’s specifications.
Step 6: Recharge and evacuate the AC system. Have an EPA-certified mechanic evacuate and recharge the AC system.