My experience with rebuilt power steering pumps is not good. In the last year I have replaced 3 of them in my car. One wouldn't supply pressure under
2000 RPM. One howled continuously and the last one did nothing at any speed. So I bit the bullet and bought a new Lexus pump. It works just like it's supposed to. The rebuilt pumps were from 2 different rebuilders. My advice is to buy a new pump unless you want to become the world's fastest pump changer and need lots of practice.