[Wally Arntzen]

I have an 88 and when I got it I was frustrated with air leaks as you are. A friend of mine who manages a bus repair garage and I decided to fix it all. We replaced every check valve, air switch, air guages, air motors and two air tanks (which had leaks in the welded seams) and to this day when I am parked and living in the coach, my 110 air compressor goes on approx 2 to 3 times in 24 hours. This is primarly due to the fact that I have an air operated toilet. It cost a bit of money for all of this equipment but it was well worth it to eliminate the problem. The air switches I replaced were for the generator slide, the step slide, the windsheild wipers and they were the most expensive.
In most cases you don't find cracked lines, it's just the check valves, switches, etc that get all gumed up over time and fail due to lack of use or moisture that causes the gumming up.