Power steering pumped groaned. Replaced. New one groans a little less loudly. Barely noticeable at idle, VERY noticeable while turning steering wheel. If the car is not moving and the wheel is slightly turned, a very slight pulsating is felt along with the groan. Mechanic and owner are scratching heads. Any thing we overlooked? 1998 S70

If the power steering feels right, then you need to make sure all of the air is out of the system. I've some amazing transformations just flushing the fluid and getting all of the air out.

It's free and usually works. Just take the p/s res cap off and crank the wheel lock to lock, over and over, hold it for a few seconds at full lock each time, for about 10 minutes.

Also, make sure the all of the line clamps are tight, and the rack isn't leaking.

Air in the system is the problem. double check your hose fittings, and do what dsmith says. Take the cap off, or loosen it, crank the wheel back and forth. Eventually you will get it stopped