I was in Ashland, VA getting ready to depart the campground and the rear of the coach would not air up after retracting the jacks.
To make a long story short, when we re-leveled the coach, I noticed the right rear air spring was completely detached from the piston and obviously would not seal and hold air.
I subsequently had it, actually both, replaced on site by a local mobile diesel service via my extended warranty and contacted Firestone the next morning.
By my photos, their assessment is that the internal bolt the holds the retention ring that secures the bellows to the piston must have come loose or broke and the cause is usually attributed to an over-extension of the air spring.
Now, I bought my coach new five years ago and I know for a fact that the rear of the coach has never been lifted in a manner to allow the axle/suspension to drop in a manner that would over extend the air spring. In fact, I even check the level of my coach inside before I deploy my jacks to ensure shaft travel is kept to a minimum when leveling.
Additionally, looking at the Freightliner XCM chassis suspension drawings, it appears that the shock would be the stop limit for the axle and suspension range (including the jacks) of travel which, I would think, would be calculated in a manner not to exceed the maximum extension of the air springs.
My conclusion is that the air spring just failed....period. But, I don't have a lot of experience with air springs and suspension systems and thought I may get some feedback from those on the forum that do.
One good thing that did come out of this is that I now know how to replace the airsprings, which is not that difficult at all provided you carry the proper tools.