Greetings all, last week I got back from a ~2,000 mile road trip. My '97 S420 ran like a champ the entire time, but a few days after I got back, I noticed that my power steering has become really loud for a few minutes after I start the car. It's loud to the point where I can feel the whine of the pump in the steering wheel itself. After a few minutes of easy driving, the whine gets less noticeable and eventually goes away all together.
I checked the fluid level, and with a cold engine it's sitting right on the 20 dec C line of the dipstick. The fluid itself still looks clear and was replaced in April of this year.
I'd appreciate any advice you could offer. Thanks!