My 2004 Acura MDX recently started making a loud squeal when it was cold. Usually it went away when the car warmed up but for short trips it was pretty constant. Also moving the steering wheel changed the pitch of the sound so I was pretty sure it had something to do with the power steering.
Nevertheless, since the car had over over 100,00 miles on it and was almost 10 years old, just to be safe, I had the timing belt and water pump serviced. Since the sound remained, I began looking into what it would take to change the power steering pump and I found a TSB for the Power Steering Moans or Whines During Cold Start-Up.
I kind of doubted that changing the o-ring would fix such a loud noise, but I went ahead and purchased the o-ring (13.0×1.9) part# : 91345-RDA-A01 for $.70 from my local dealer along with some genuine Honda power steering fluid. I followed the TSB instructions to replace the o-ring and also changed most of the power steering fluid. It took a total of about 30 minutes and unbelievably the sound was gone.