Power steering

[diyanich]

Hi guys,

I just got alignment done on my X and started to hear the steering pump noise while sharp cornering at about 20 km/h ...so I just tried to spin the st wheel while in P and I can hear the noise,it's not that loud,but..one thing draw my attention,when I turn the st. wheel not to extreme let's say,in 1/2 second it jerks back about 15°..why would it happen?
I am planning to change the fluid before it's too late.
BTW how often should I change it?did 20,000 kms since bought the X no fluid refresh by me and don't know if there was any in the past,but it's pretty pinkish transparent yet.

any ideas why it's acting weird?

Thanks