How to change cab air bags

In this tutorial I'll be changing the drivers side cab air bag on a 2006 Freightliner Columbia. It's a pretty easy job and should only take about 15-30min to change using minimal tools. It's also suggested that you change both of them while you have all the tools/supplies out....but it isn't necessary. The part # is 18-52651-000 and costs about $65.


1. Turn your truck on to air it up. This will make jaking the cab up a whole lot easier. While the truck is airing go ahead and detach the air leveler using two wrenches (or wrench and socket). I used an 11mm wrench to hold the screw head while using a 9/16 socket to uncrew the nut. Once the leveler is free press it down slightly to pump more air into the bags. Once you've reached a comfortable height level out the lever to maintain that height.


2. Place a scissors style jack between the frame and cab to support the weight of the cab once you turn off your truck and cut off the air supply. Engage the jack a few times to put it under pressure. You'll also want to place supports on the opposite side too. In this example I used a scissors jack and two wood blocks.
Drivers Side Passenger Side

3. Turn off your truck. Use the air leveler to dump the air from the cab air bags (push the leveler up).


4. Take a flat head screwdriver and pry both ends of the of the bag from the frame. Don't worry, there's no need to be gentle. You're trashing this one....right? Right???????


5. Disconnect the air line but using your flathead screwdriver to push up (towards the bag itself) on the brass fitting to release the line. This might be somewhat difficult given the grease/grim build up. No worries. Take some WD-40 (or equivalent) and spray the fitting. Work it in. Also rotate the air line back and forth to loosen it up as well. Eventually, you'll be able to release the line. Hook up the new bag in much the same manner. Push in the fitting, insert air line, and release. Simple.


6. Remount the air bag to by simply pushing both ends into into their respective holes. Don't worry about bending the bag, it'll air up and form just fine. In fact, you should still have enough air in your tanks to air these bags back up without needing to turn your truck on again. Just use the leveler.


7. Air the up and remove your supports (jack and wood blocks). Perform a leak down test. Everything should be good to go. Pat yourself on the back and go eat a cookie