When I installed a new power steering pump it said to cycle from one stop to the other a minimum of 40 times!
To be honest at about 20-25 I gave up I had noot seen any bubbles or change in fluid level in the reservoir after about 12-15 cycles. Started for about 1 minute then cycle a few more times fluid level did not change and no bubbles so I called it good.
A mechanic buddy said they use a vaccum pump on the reservoir cap, but I didnt have to material to make a sealed cap that I could hook to a pump. It was the weekend and I needed it running Mon.