My truck is about 12.5 years old and while it's easy to tell if most of the parts still work (headlights still come on, brakes still stop the truck, fuel pump still sends fuel to the engine, etc, etc) how do I tell if things like the air bags still "work"? Short of crashing my truck into a tree, is there any way to test the air bags? I'd hate to get in a wreck only to have my air bags not deploy because they are so old. Do air bags go bad?