Power steering

What is your question?

I took my car for tie rod ends. Then they told me I needed a rack and pinion. After all that was done the power steering mysteriously stopped working. They replaced the power steering pump and it still was only working half the time. Now they have replaced the power steering lines and it still goes in and out. I am $1000 in the hole and have power steering maybe 30% of the time. It is like arm wrestling with a gorilla going into a curve then it will get real loose causing me to nearly lose control. Please, tell me what else it could be!