I have a 2004 Country Coach, what is the expected life span of the air bags? I’m the original owner, I have 89,000 miles on her and I just installed my third set of shocks.
We have had ours inspected because we were worried about it as the OP is. Motor trucks told us we had the new type (what ever that is) and not to worry, they would never need replacing.
I happen to own a coach that absolutely requires that the airsprings in the rear suspension are functional. That is all it has and if one goes out (on my coach's vintage) it cannot be moved.
The real answer to your question is very dependent on the model and manufacture of the specific part. The OE for the coach had a life of about 20 years. The newer replacements seem to only last about 15 years. I personally would have to go with current manufacturing processes and vote that like tires, start worrying at 10 years.
On the Prevost site, they recommend that 10 yrs. is a good time to replace the airbags. The bags can develop leaks as they age. You certainly don't want to be out on a trip and 'pop' a bag!
We found out when we were at Josam's in Orlando getting new tires that our air bags looked very worn and it was suggested we replace them. They are very cracked near the bottoms, so for piece of mind we are having them replaced on our way out of Florida in a few weeks. 2007 coach with 129,000 miles with 1 trip to Alaska.
I've thought about buying a spare one (My 04 Dynasty has 10...all the same)...8 are easy to see and they still look like new. I do carry a 9" block that would do in a pinch...some have run without one of the outboard airbags on their Monaco to where they can get it fixed. 83K miles and original shocks.