Gary, you would be amazed at how many folks will go under a bus that has been raised on its air bags. When I am under mine IN THE PIT I still put the jacks (jack down, adjusting screw fully extended) under the support point. At least that way I have a total mechanical support that cannot possibly have a hydraulic failure.

When I work on the suspension, or any part of the air system, I have two jacks under the support point, as we did when Roger and I changed air bags on our buses.

I have had my bus raised up by the Detroit/Allison dealer and like Prevost they used the four floor lifts that go under the tires with a pair of forks. Unlike Prevost the forks under the drive axle went under a single tire instead of the pair of tires. I would be scared to death that the tire would blow and the sudden shift would bring the whole thing down but they were totally unconcerned. The only thing I did although it probably didn't make a bit of difference was to dump the air from the air bags so the drive axle air bags were not totally collapsed with full air pressure like the tires were.