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HOW TO: Maintain your truck’s compressed air systems this winter

ELYRIA, Ohio – With cold weather approaching (or already arrived in some parts of North America) maintenance of compressed air systems becomes vital for fleets and owner-operators throughout Canada and the U.S.

Bendix Commercial Vehicle Systems, which develops and supplies safety technologies, energy management solutions and air brake charging and control systems and components, offers some advice on how to ensure your air system runs smoothly this winter season.

Winter’s water woes

Freezing temperatures can wreak havoc on the moisture contained in a truck’s air system, and can condense inside the air tanks and into the rest of the braking system, and subsequently freeze, causing malfunctions in the brakes and valves.

“Air dryers have become increasingly critical as they protect not just braking systems, but the full range of components that use compressed air to help control things like automated manual transmissions, emissions controls and other automated functions,” said Richard Nagel, Bendix director of marketing and customer solutions, air charging. “During winter, a number of factors can degrade a dryer’s ability to effectively remove moisture from the air: Trapped water can freeze and prevent valves from functioning properly; the stress of freeze-and-thaw cycles creates additional strain on components; and chemicals applied to roads can corrode the dryer’s purge valve.”

Replacing your air-dryer cartridge

One of the easiest ways to keep moisture out of your truck’s air system is to replace the air-dryer cartridge every fall before the temperature takes a nose dive.

Older air dryers could require a proprietary-style cartridge, while the more common spin-on cartridge is used for newer air dryers, and often contains less desiccant material than some of the older style designs.

Bendix recommends using OE and oil-coalescing cartridges to best ensure the use of reputably-sourced and effective air-dryer technology and to avoid oil deteriorating seals and contributing to premature damage in a slew of other components.

Air tanks and purge valves

Manually draining your truck’s air tanks can also help alleviate moisture issues in winter, up to once a month for those with high-air demand and every three months for a typical line haul truck.

Bendix says an air dryer’s purge valve is especially susceptible to contamination in winter due to the abundance of water, chemical treatment, salt and sand used on many roads.

“On vehicles operating in conditions involving long-term exposure to cold or contaminants like road salts, an annual purge valve replacement using an OE component is good preventive maintenance that can be scheduled along with installation of a new dryer cartridge,” Nagel said.

Tackling system freezes

Bendix ‘emphatically advises against’ the traditional system freeze-up fix of adding alcohol, methanol or a similar de-icing solution to affected areas, as this can corrode or contaminate your truck’s components, or break down valve lubricants.

Instead, Bendix says to determine the precise location of the freeze-up and limit application to that specific area, which will minimize exposure to the other areas of the air system.

It is also important to check for leaks around the brake valves if the O-rings were exposed to an anti-freeze solution, and if the valve is leaking, either replace the O-ring or the entire valve.

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1 Comment » for HOW TO: Maintain your truck’s compressed air systems this winter
  1. Erik Johnson says:

    Using an automatic drain valve on the wet tank will get rid of the water and oil that gets passed the air dryer. No more alcohol in the system!

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