I drain the moisture from the muffler and the other four locations every time I run mine. Even if for only twenty minutes. My leveling arms have external check valves (PD4905), I have replaced the two rear. What a difference that made in keeping the air in the bags
Will replace the front leveling arm check valve tomorrow.
I did add a lanyard valve to he rear tank in front of the axle and ran it to the edge of the wheel well so i can reach it in front of the tire. I knew if I didn't do that the rear tank would never get drained as I would have to crawl under the bus every time to do it.