Just a testament to bags... I had a tractor brake cam over one time. Caught the tire on fire, the drum was so hot. My boss brought me another truck down, and I pulled mine across the street, and set the parking brake. (Yes, I set the parking brake.)

I should have chocked it. Didn't think about that. "Where's your truck?" "Right over... Uhhhh."

It had rolled a long way down a hill, and smacked into a tree stump really, really hard. Those airbags were stretched out like rubber bands, and I damn near ripped the axle off. Oops.

When the boss got it home, he did some jiggling or other to get the axle freed up, and it snapped back into place. The airbags were fine, and stayed with the truck for the rest of its life.

They do go out once in awhile, but I only noticed the boss replacing a couple of bags in 10 years. Those things are impressively tough.