Windstar 3.8 Mod 2000, noise in Dir. Hydraulics

Good afternoon, I would like to know if someone can help me, again;

It happens that I have a Windstar Mod. 2000 Machine 3.8, it turns out that the Hdraulica steering pump makes me noise, I change it 3 times, and it still does the same, I change the high hose, and it remains the same, the zipper also changed it.

I already pounded, according to the manual, well, I based on the All Data Repair program . After the purge process, the noise is removed, the steering wheel is soft, but I accelerate and begins to grow again.

I hope someone can help me. Thank you.