When To Replace Air Dryers In Heavy Duty Trucks

Air Brakes On Commercial Vehicles

Most of today's commercial fleet drivers choose to drive heavy-duty vehicles with air brake systems, and it is no wonder why: air brakes are cost-effective, environmentally friendly and more reliable than traditional braking systems. These drivers rely on clean air filters in their system to protect their vehicles avoid brake failure, and to ensure that the system works properly, drivers trust air dryers to rid harmful pollutants, such as oil and moisture, that can potentially reach the supply tank and damage air valves, air brakes, and even the engine.

What Is the Air Dryer In a Truck?

Commercial and Semi Truck Air dryers are located between the compressor and reservoirs and work hard to remove solids, liquids and vapors that can damage the entire air brake system. Here's how it works: When warm air meets the air compressor, the moisture will condense (cool) on the walls and drain down into a purge valve - where filtration takes place roughly every 15 seconds to separate and treat air particles cycling around the compressor. The governor kicks into gear at this point and will signal the purge valve to open and force air and harmful contaminants out. This process helps rid contaminants keeps air brake systems cleaner and longer-lasting.

How Will I Know If the Air Dryer Goes Bad?

Large trucks, even school buses, should seek replacement of air dryer cartridges every year or 100,000 miles. Double and triple-haul trucks can go without replacement for two years, or 200,000 miles.

Heavy trucks are just like any other vehicle – they require maintenance, and it may be difficult to pinpoint what is wrong with the vehicle without expert diagnosis, butif you are hearing or seeing these symptoms, chances are it is time to replace your air dryer.

Symptoms of a Bad Air Dryer

Air dryers may fail due to leaks, clogs, worn parts, and electrical issues.

Air leaks are one of the most common reasons for failing air dryers in trucks and should be checked regularly. The good news is that leaks around the compressor are fixable and can be tightened with basic hand tools. Clogs can lead to poor filtration in the system and block purge valves, and worn parts, such as seals, can invite pressurized air in. We don't want any of these issues to occur; however, the electrical issues are what drivers really need to look out for including signs that the compressor is not starting or stopping. These could be because of bad circuit breakers and pressure valves. The compressor may create a loud ticking noise maybe due to loosen parts, as well.

How To Test Purge Valve On Air Dryer?

Grab two supply lines for testing. Find and plug the delivery port on tank and then take a line and fill the supply line with air. Let the dryer fill, if the compressor has a leak, you will learn it now. Then, take your next supply line, and fill the control line and let the purge line empty out. If it is good, it will naturally come to a stop. This is a simple way to quickly and efficiently test purge valves on air dryers.

Who to Trust For Air Dryer Replacement?

Bendix is one of the most trusted names in the industry when it comes to air treatment units, and it is recommended to start with them for affordable air dryer systems. The air dryer is an important component for vehicles with air brakes and should not be neglected during routine check-ups and maintenance work.