Paul, you may still want to take a look at the leveling valves. We have seen them get contaminated from oil coming from the compressor. If you look at the port on the bottom of your air dryer, and see a fair amount of oil, or can see any oil on the bottom of the leveling valve ports, that is your likely problem. If the valves get contaminated with oil, they will stick and be slow to respond. Generally replacing the leveling valves, and servicing the dryer will eliminate any future problems. Charles, Prevost has updated their information on the proper air bags. Make sure you provide them with your vin#, and make sure they know it is a motorhome.