Air Dryer Purge Constantly Going Off In Cold Weather on Freightliner Cascadia?
Note this post may have more details added over time.
This can happen even in warm weather, but during the colder areas you might notice this more often. You might get advice that your truck might need a repair, new cartridge, valve etc., but this might not be the case. Usually by draining air tanks you can fix the issue yourself especially if you never do it. If you have been draining all your air tanks already and still get moisture buildup then you might have another issue going on. Read below if you are having issues with the valve popping off too often and don’t drain air tanks usually.
Note there are two pull cords up front of battery compartment for the two tanks under driver. Then a third pull cord in back for rear, the front inner tank usually has the most moisture. Three in total to drain on my 2024 Freightliner Cascadia.
Park your truck on level ground, set your trailer brakes or chock wheels. On my 2024 Freightliner Cascadia there are three tanks with pull cords on each side of battery compartment, get yourself a rubber tarp strap and hook them up to pull cords and catwalk to let drain. The front outer tank generally has a ton of air and will take a few minutes to fully drain and why we use straps. The front inner tank is where I usually see moisture, the lone rear tank doesn’t have much of anything in it usually.
If one of your tanks has a bunch of water spraying out make sure to fully flush it. Drain then start your truck while it’s almost empty and let it build more pressure to keep pushing out more moisture.
Next time you park and truck is running it should stop purging excessively if this fixed the issue. Remember if it’s freezing outside the old moisture could still be frozen. If it’s been cold try doing this in a warmer area if possible, you may see videos of trucks doing this with tons of water. This typically isn’t the case but there is moisture you won’t see in the air, this is the stuff giving us issues. Also make sure you are draining all of your tanks, some may think they have just one.
Draining air tanks isn’t just about removing air, it’s to remove built up moisture in the system. This air is the same stuff making your automatic transmission shift, you don’t want moisture in it that could possibly freeze.
You should do this daily or try for at least 3 times a week, it’s a simple habit to learn by using a tarp strap on pull cords and let it do its thing. Should you drain it for a few seconds or fully? Let all air fully out using a strap is my personal preference, not all moisture can be seen.
