I rebuilt my ZF Power steering rack by replacing all the seals. All went OK with not too much difficulty. It was in good shape internally, no groves or flat spots. I think I got it back together the way it was, but the proof will be when I start the engine. Now that it's together I am wondering if I should have filled the main tube up to the top . I did add a lot of new power steering fluid but there must be some air in the cylinder, and for sure the hydraulic lines. Will the air self bleed out or do I need to perform a bleed prior to installation. Don't see any ports or opening that would facilitate a bleed so I'm not sure how to proceed. I could remove the lines at the control head, place them in fluid container and operate the rod, vacuum would pull fluid and should fill the main body completely, one side at a time. OR will the power steering pump charge the system and remove the air?