As long as he kept the fluid in the box he should have been OK. I primed my box and pump as I installed them and they were bone dry before that. Still got air out of them both in the beginning but as long as they're primed it will eventually work the air out.
What is your point with this post? In one sentence, you say he will be OK, and then you turn around and say you got air out. You really confused me, sort of like Hillary on some of the issues.
If you put a new component into any hydraulic system, you need to bleed the whole system. Any time that any air is induced into the system, the pump will mix it up and you will not only get the froth but billions of tiny air bubbles it the fluid that will spread throughout the system. Why wait, bleed the box so the air does not have to work its way back up to the reservoir causeing more bubbles.
