Why is power streering hard to turn?

What is your question?

I changed a very noisy ps pump and the noise is gone, but the steering is still hard to turn. It is very possible the owner drove with very low fluid and topped it off with power steering fluid with stop leak. Bummer... Bleeding bubbles yelded very little improvement to the turning. However I was not able to get rid of all bubbles. Could there be some damage in the rack and pinion?