How to Avoid Frozen Air Lines in Winter

How to Avoid Frozen Air Lines in Winter

In winter, fleet drivers face weather-related challenges that can impact their safety on the road and the safety of other motorists. While weather conditions can’t be controlled, you can mitigate the impact of severe weather on your fleet operations by being proactive and winterizing your vehicles.

Winterizing vehicles involves conducting preventive maintenance checks on a wide range of vehicle components, including:

  • Air system
  • Engine and fuel system
  • Battery voltage
  • Brake system
  • Heating and defrosting system
  • Lights and electrical system
  • Exhaust system
  • Tires
  • Fluid levels

While preventive maintenance checks on all of these components are essential to keeping your vehicles running smoothly throughout the winter, for purposes here, we’ll take a closer look at a component that can sometimes be overlooked and one that winter can be especially tough on — the air system.

Air: Not to Be Taken Lightly

Since vehicle systems rely on compressed air for braking and non-braking functions, including air suspensions, automated manual transmissions, and safety technologies, clean, dry air is crucial for safe and smooth vehicle performance.

Just as moisture in fuel can cause problems, moisture in a vehicle’s air lines and valves can impact the operation of the air system and increase the chances of malfunctions in brakes and valves. While moisture can be a problem in every season, winter is particularly problematic since the condensed water is more likely to freeze.

Here’s how freezing can occur.

When the compressor draws in air, moisture is brought in as well and the compressor pumps both into the air dryer. The air dryer’s purpose is to stop moisture dead in its tracks — to prevent it from going further. If the air dryer fails in its purpose and moisture goes past the air dryer, the moisture can condense inside the air tanks, and progress to the rest of the braking system where it can freeze and create a blockage that impairs the braking system.

An impaired braking system is a disaster waiting to happen. The good news is there are steps you can take to help keep moisture out and the chances of freezing and blockages down.

Let’s look at five steps that can help you accomplish that.

Check the Air Lines

Make sure the discharge lines slope downward from the compressor discharge port with no water traps, kinks, or other restrictions present. Additionally, make sure the lines aren’t drooping. Drooping lines can cause water traps, which can freeze.

The maximum length of a discharge line is 16 ft. The last three feet of the discharge line — including the fitting at the end — should be insulated with ½ in. thick closed-cell polyethylene pipe insulation to retain heat and reduce the likelihood of freezing.

Stay on Top of Air Dryer Maintenance

Regular maintenance and inspection of the air dryer is crucial to keeping moisture out.

Check for air leaks and inspect the dryer cartridge for any damage. Check that the purge valve and governor are working and that the air dryer heater is functioning. Check for blockages in delivery lines, examine the desiccant for saturation, inspect and check that valves are working, and the air compressor builds enough pressure.

Lastly, a good rule of thumb is to replace the desiccant cartridge in the fall.

Drain the Air Tanks

For clean and dry air, the air tanks need to be routinely drained. One method is for the driver to drain each tank after returning to the yard or terminal and after turning off the engine. Another method is for the driver to open the drain cocks on all tanks and leave them open overnight so that all air and contaminants drain by morning.

Automatic drain valves are another option and remove the driver from the draining process. If installed, check that they are working before cold weather sets in.

Use Antifreeze

Adding antifreeze solutions to the air brake system lowers the freezing point of moisture and helps prevent the formation of ice within the air lines. Just make sure to check with the vehicle manufacturer or your mechanic to determine the appropriate solution for the vehicle.

Park Strategically

When parking for extended periods in cold weather, drivers should choose a location with minimal exposure to the elements. Areas with strong winds should always be avoided since winds can accelerate heat loss from the vehicle.

Ideally, a sunny or sheltered spot is best for mitigating the risk of frozen air lines. And for mitigating the risk of an unhappy and unproductive driver.

Need help protecting your fleet against the elements? Download our full guide on 365 Days of Fleet Protection here.