As I was doing the ATF flush today, I noticed a steady stream of air bubbles on one side of the PS pump reservoir. The van had been running a while, as I was checking for leaks after the ATF flush. Is this normal? Nothing really wrong with the steering, although it feels a little stiff to me. That said, I just came from an '08 Toyota Highlander with electric steering which was very easy to turn (too easy, IMO).
At first I thought the fluid was boiling, but I think it's just air. It's an '07 EX-L with 41K. Any ideas? If not normal, is it harmful?