RAV4 Diesel 2003 Power steering system

[Sukie]

Hi,
on my RAV4.2 2003 Diesel

I have some issue with the power steering , at low rave I get some reverse hits at the end of each direction, and look like to loose power for a fraction of seconds. Can be:
- A good flush needed
- A Slipping belt
- The Pomp is gone
- What else?

I did flush the power steering system with recommended fluid 3/4 of a gallon, and when I clean the fluid container, oh surprise, no filter inside, is that normal?

The problem is still here any idea? 

Thanks for your time