[The Newell]

I know, Not what you wanted to hear but Finding small air leaks can be time consuming but eliminating them is worth the effort. There is no reason why our coaches should not maintain air pressure the same as your tires. One of the best and cheapest ways is to buy 'Bubble Soap' from the toy store. When sprayed or brushed on hoses and fittings it sticks in place and does not evaporate immediately. A very small leak will produce a mountain of bubbles. Just make this a long term spare time project. Do one area at a time and it doesn't get too boring. You also learn a lot about the air system as you do it. One leak that is very hard to find and not always consistent is if the compressor governor is leaking back.