Air piping services

How to Avoid Freezing Truck Air Lines in Winter

Let’s talk about airlines — and no, I’m not talking about Delta or United. It’s that sometimes overlooked but important component of your truck, one that becomes especially vital to staying in good shape as winter approaches. The effects of winter weather conditions on the air lines can adversely affect the performance of the truck’s brake system, which also exposes the truck to a CSA violation. Simply put: you don’t want these things to freeze.

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The # 1 problem airlines face, according to Rich Nagel, director of marketing and customer solutions, air supply and transmission at Bendix, is moisture in the air system.

Humidity is a problem at any temperature, ”he explains,“ but in cold weather condensed water can freeze, increasing the risk of brake and valve malfunction. When the compressor sucks in air, it also introduces moisture and pumps both into the air dryer, which has the job of preventing that moisture from seeping in any further. If moisture passes through the dryer, it can condense inside the air reservoirs and end up in the rest of the brake system, where it can freeze.

For this reason, Nagel says, air dryers have become increasingly critical.

“They protect not only brake systems, but the entire range of components that use compressed air to help control things like automated manual transmissions, emissions controls and other automated functions,” a- he declared.

“However, winter conditions can adversely affect the truck’s air system in several ways. One is trapped water, which can freeze and prevent valves from working properly. Another is the stress of the freeze and thaw cycles, which places additional stress on the components. A third are chemicals applied to the roads, which can corrode the dryer housing, purge valve, and pneumatic fittings.

As Phillips Industries wrote in recent technical advice: “For safety reasons and in accordance with SAE regulations, overhead lines must be able to stretch and reverse properly. When the air lines can stretch to a suitable working length, the force on the coupled gladhands is avoided. When they recoil properly, they stay off the deck plate.

If temperatures are too cold and drop below the operating temperature of a coiled air line, the air lines can lose their ability to stretch or recede, the Tech Tip continued.

“If the air lines lose their ability to stretch, a force is applied to the free hands and can separate or even withdraw completely, causing a loss of air pressure in the brake system. The stiffness of the air lines can also cause kinks, which can trap air in the brake system and permanently damage the air lines, ”Phillips said.

“If the air lines are stretched too far in extremely cold weather, they may not revert to their original state and sag. This creates the potential for drag damage on the deck plate. In very extreme cases, the tube may crack and / or even separate at the fitting. Air lines are also susceptible to damage when gladhands freeze together. If an air coil does not have handles, a driver can exert too much force on the lead when pushing down or pulling up when trying to disengage the hands free. This can create a twist and even possible friction on the tube.

Three stages of preventive maintenance

You may be wondering how can I prevent this? The good news is that there are a variety of preventative maintenance steps you can take, both in the winter and ahead of time, that can alleviate this problem.

One solution, according to Phillips, would be to use air lines specifically designed for extreme weather conditions, capable of remaining flexible in cold weather. Another protective measure would be to select air ducts with handles or easily add hand extension handles to your existing assemblies. Extension handles provide better leverage to help avoid applying too much force when coupling and uncoupling.

Bendix ‘Nagel recommends focusing on three steps:

  1. Replace the air dryer cartridges every fall. Equipping an air dryer with high quality original equipment, supplied by the manufacturer, is one of the easiest and most cost effective steps to help keep moisture out of a system. ‘air,’ Nagel explains. “Bendix recommends oil coalescing cartridges like PuraGuard because oil aerosols passed through the system can be particularly harmful to air drives.”
  2. Manually drain the air tanks. You need to do this periodically, depending on the air consumption of the truck. “Manual draining of trapped water from the tanks is a safe method of removing it from the system and indicates proper operation of the air dryer,” Nagel explains. “We recommend draining the tanks up to once a month for vehicles with high air demand or every three months for a typical line haul truck. “
  3. Check the dryer purge valve for corrosion or sand buildup. You should replace it if necessary. “Corrosive road chemicals can damage the purge valve and the area around the air dryer where the valve is mounted. Installing a new one as protection is a relatively quick and easy preventive maintenance operation, ”Nagel explains.

Sometimes, despite best efforts, parts of a vehicle’s air system freeze, he adds.

“Avoid using alcohol or similar de-icing solutions, as they can remove lubrication inside brake valves and degrade o-rings and valve seals,” Nagel recommends. “If you have to take this drastic step, try to determine the precise location of the gel and limit the application to that area, it will help minimize potential exposure to other areas of the air system. Also check the brake system and replace any slow or faulty valves. “