Power Steering pump

[PuroCumminsPower]

I changed pump and added oil. I started it and at first I couldn't even turn steering wheel. I shut truck off , waited tried again and it turned real easy. Day after I left to work and its hard to turn again. Its when I'm at a complete stop and its worse when turning left. Steering wheel makes noise as well. I have to give it a little fuel to turn easier. I had gear box changed about a year ago. Any ideas?