Yesterday the alignment shop checked the inner tie rods and steering rack for play. When I drove out of the shop, the steering ground loudly when I turn left or right from center. I thought they moved the inner tie rods in and out or turned the front wheels without turning on the engine and using the steering wheel, so air got into the steering fluid (Mobil 1 ATF). Today, I flushed by disconnecting the return line to the reservoir and refilling it with two quarts of Mobil 1 ATF. Sure enough, the fluid that first came out looked like strawberry milkshake from so much air. After no bubbles came up through the return line, I reconnected it. I see no bubbles coming up in the reservoir either, but steering still grinds loudly. Please, give me a diagnostic and cure. Best regards to all.