That's how I've always bled power steering systems that I've worked on. they "self bleed" through use. First start up, I turn the wheel lock to lock several times. Of course, this will aerate the fluid full of bubbles. I shut it off and let it sit a few hours, or a day to let the bubbles percolate up and for the fluid to "settle" Then I top off and do it again.

Usually this is enough to get enough air out of the system to take it for a drive. I will come back a week later and check fluid level and top off as needed.



Now, for the cummins issue...I've read quite a bit about the power steering 'whine' that sounds like it's coming from the dash. Stepping on the brake causes the noise to go away. there's a lining in the power steering hoses going to the hydro boost that can separate. There's a youtube video of a guy unhooking his lines, removing this liner, and reinstalling everything. Lots of guys on Cumminsforum have had luck doing this.

I tried it with mine, but when I unhooked my hoses, there was no sign of a separated lining, so I'm dealing with a hiss still.
Don't know if I need to go after the hydroboost unit on the firewall, or if my pump is acting up.