What You Need To Know About Oil-Coalescing Technology

Know what questions to ask before buying your next oil-coalescing desiccant cartridges for your heavy-duty air treatment system.
Heavy Duty Mechanic

Overview: Understand Air Dryer Oil-Coalescing Cartridge Technology

Maintaining your heavy-duty air brake system is vital to the longevity, reliability, and performance of your vehicle, not to mention it decreases the risk of failure and downtime, reducing cost. Protect your semi-truck or your other heavy-duty applications by choosing the best oil-coalescing cartridge for your air filtration system. 

At Wheelco, many customers ask questions pertaining to their truck’s air system, specifically heavy-duty, oil-coalescing cartridges. In this article, we will review:

  1. What Are Heavy-Duty Air Cartridges Purpose?
  2. Why Are Oil-Coalescing Cartridges Important?
  3. Why Is Oil Bad for Your Air Dryer System?
  4. Standard Cartridges vs. Oil-Coalescing Cartridges?
  5. What’s The Difference Between Bendix vs. Wabco Oil-Coalescing Technology?
  6. How Often Should An Oil-Coalescing Cartridge Be Replaced?
  7. Wheelco Oil-Coalescing Cartridge Recommendations

What Are Heavy-Duty Air Dryer Cartridges Purpose?

The air supply for a heavy-duty air system is generated by an air compressor. This process generates extreme amounts of heat. As the compressed air cools, condensation, or moisture, is generated within the system. The air compressor will also omit small amounts of lubrication in the system from the compressor lubrication system.

Consider that an air compressor can pass up to one liter of oil in one year. The air dryer is your in-line filtration system which prevents contaminates, such as water vapor, oil droplets, and small debris, from reaching your air system components.

The air dryer cartridge’s primary job is to trap these contaminants from the system, allowing them to be discharged from the system. This will help prevent damage to your air valves and other air components.

When your filtration system is running smoothly, it prevents freeze-ups in the winter and aids in the prevention of airline failure. 

Wheelco Quick Tip: The presence of water in your air reservoir may indicate that the air dryer cartridge may need to be replaced.

Why Are Oil-Coalescing Cartridges Important?

Trucks with newer emission controls and automated manual transmissions – contain air actuated solenoid valves. These solenoid valves are typically more sensitive to contamination than traditional brake valves.

A cartridge with oil-coalescing technology is designed to remove oil aerosols from the air system more efficiently.

Why is Oil Bad for Your Air Dryer System?

Oil has a reputation of causing premature damage to oil sensitive components, such as brake chamber diaphragm, seals, spring brake modulating valves, push-pull dash valves, air actuated solenoid valves, and more. Not only this, but if oil gets into your engine emission systems or air actuated solenoid valves for your drivetrain systems, it can wreak havoc on the overall performance, reliability, and fuel efficiencies of your vehicle. Therefore, when your air brake system becomes compromised, it can result in costly repairs and downtime.

Standard Cartridges VS. Oil-Coalescing Cartridges?

Standard Cartridges

Standard desiccant cartridges are designed to eliminate moisture, small particles, and debris, and can trap some amounts of oil aerosols. These types of cartridges aid in removing water vapor from the air line, but limited oil or aerosol (oil vapor). 

The most important element of an air dryer cartridge is the desiccant. And not all desiccants cartridges are created equal. Even those desiccants considered good aren’t always suitable for an air-brake application where the dryer cartridge is exposed to high temperatures, water saturation vibration, drastic temperature changes, and pressure cycling. Failing desiccant can begin to clump, and at this point, it not only stops removing moisture but eventually turns into a powder that can get into the air system and contaminate your brake valves.

Oil-Coalescing Cartridges

Oil-coalescing desiccant cartridges trap moisture, oil vapor, debris, and small particles allowing it to be discharged from the air system. Thus, oil-coalescing desiccant cartridges are being used more and more on new trucks and vehicles in the aftermarket. Why? To abide by the new emission control regulations. The engine tends to run at higher temperatures which generate more heat in the air system. This causes oil vapor (aerosol) to occur. Thus, the need for oil-coalescing cartridges. Because this type of cartridge eliminates more contaminates, the result is cleaner air.

Traditional vs. Coalescing

Wheelco Quick Tip: If your truck is equipped with an oil-coalescing cartridge, replace it with the same product. We recommend replacing your air cartridge with the same brand and/or technology.

Bendix VS. Wabco Oil-Coalescing Technology  

At Wheelco we carry two different types of quality oil-coalescing air cartridges. They are both quality products. Each brand has a unique patented filtration system to remove oil aerosols. The oil-coalescing desiccant cartridges are the same size as standard cartridges and have the same mounting thread.

Bendix Oil-Coalescing Technology

As the air passes into the air dryer, most of the oil droplets are removed by the oil separator. The air then moves through the desiccant material which removes most of the water vapor before the compressed air is passed to the air brake service (supply) reservoir. The oil droplets and the water collected are automatically purged at the dryer when the governor reaches its purge cycle.

For vehicles with accessories that are sensitive to small amounts of oil, oil-coalescing air dryers are used. Similar in appearance to standard air dryers, PuraGuard oil-coalescing air dryer cartridges contain a coalescing media at the inlet of the desiccant bed that provides a high level of oil removal.

Check Out This Bendix Oil-Coalescing Technology Infographic!

It explains the process of Bendix’s oil-coalescing technology in easy to follow steps.

Bendix PuraGuard Oil Coalescing Technology

Watch This Bendix Oil-Coalescing Technology Video

It explains the process of Bendix’s oil-coalescing technology in easy to follow steps.

Wabco Oil-Coalescing Technology

The Wabco oil-coalescing technology combines fine droplets into larger and heavier oil drops that cannot be carried forward by the compressed air.  The drops are captured by the coalescing fleece, which cleans the compressed air from oil aerosols.

The coalescing fleece if composed of multiple layers, each providing additional filtration which results in a cleaner and a more reliable air system.  Most of the captured oil is expelled during the air dryer purge cycle.

Check Out This Wabco Oil-Coalescing Technology Infographic!

It explains the process of  Wabco’s oil-coalescing technology in easy to follow steps.

Meritor Wabco Air System Protector

How Often Should an Oil-Coalescing Cartridge Be Replaced?

Complying with a regular preventive maintenance schedule is crucial to keeping a vehicle’s air system clean and ensuring superior performance. Bendix and Wabco cartridges should be replaced every two years for on-highway applications and annually for severe service applications.

Wheelco Quick Tip: Generally, if more than two tablespoons of water are found in the wet tank it is time to replace the cartridge.

Wheelco Oil-Coalescing Cartridge Recommendations: Bendix, Wabco and Gritline

Wheelco offers both Bendix and Wabco oil-coalescing cartridges.  Each consists of their own technology to remove the above-mentioned contaminants. Wheelco also offers our Gritline cartridges with both the Bendix and Wabco oil-coalescing technology.

Next Step: Schedule a Service or Talk to an Expert

Need assistance in choosing the right part, scheduling a service, or do you have more questions about our recommendations? Our aftermarket experts and service techs are ready to help you get exactly what you need. Simply text us, talk to us through chat, give us a call or stop by one of our stores today. We’re here for you however it’s most convenient.

About Wheelco Truck & Trailer

At Wheelcobeing customer driven is more than just a motto we live by. It means that our employees will do everything we can to best serve you, our valued customer.

Customer driven is more than just offering you advice, giving time-honored service or contributing the latest tech-support. It’s about being there—whenever and wherever you need us—in-person, over the phone or online.

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