I was also having an issue where a piece of ice would keep my primary air tank from airing up. I would be driving down the road and I would slow down for an off ramp or school bus and the primary air tank would not air up. I put my old thinkin’ cap on and determined that I needed to do the same thing between the compressor and the air tanks. This worked too.
The best thing to do is drain the water out daily during the summer and change your air dryer filter on a regular basis.
Anyway, hope this helps someone.