I reused the old dust boots on the rack. I did not notice anything like that. I want you to top off the power steering fluid. Then start the car and turn the steering wheel all the way to the left and hold it for 3 seconds. Then turn to the right all the way and hold it for 3 seconds. Do that 4 to 5 times and this will bleed the system.

The way this system is designed the fluid is rushing back to the reservoir with good pressure. It will swirl the fluid pretty fast and could cause air bubbles.

If you want you can take a pick or a nail and put a small hole in the dust boots to allow the air to escape while turning. If you think that is where the air is coming from. I would put the hole on the bottom side so that water will not enter the boot. I would take a paper clip and get it red hot and poke it through and that would be enough.

I know that some cars like on older fords they had a air pressure relief tube so that when one dust boot is compressed the air from it will be pushed on the expanding boot on the other side.