Just replaced power steering pump, sounds terrible, need to prime it?

I just replaced my power steering pump along with alternator and a number of other things, but when I started up my van today the power steering pump was making an awful grinding noise. Do I need to prime the power steering pump? Could this be the cause of the terrible sound?

You can bleed it out by removing the return line to the reservoir (not return to pump) and with the van running collect the fluid until there are no bubbles. Have extra fluid handy. It helps to have the front end on jack stands and get a helper to turn the steering wheel full turns side to side while doing this.

I assume you checked the power steering reservoir level? Make sure the level is correct and there are no bubbles/foam at the surface.