ORIGINAL: crash_expert
"DavidR" I like your method on fueling the UAT first and allowing it to sit for a little while before you fuel your mains.
In looking over the directions again and thinking about the principles behind the UAT. It would seem that as long as you have it saturated and never allow it to run empty you should be OK.
I always make sure not to run the UAT empty. If it is mounted vertically, the UAT can't be drained by defueling either because the fill line is at the top of the tank. When the main tanks empty out, the defueling pump will start sucking air, leaving the UAT full.