2000 Dodge Intrepid My Power Steering makes a loud noise

Hello I recently had my power steering pump replaced because my car was always making a loud noise while it idled and got louder as I accelerated. Well when I replaced the first pump it was even worse. Not only was it noisier but also when I would turn my wheel the car would make this grinding noise as if the p.S pump is struggling. So I yet had another one installed and it continues to do the same thing. I am able to get it quiet by turning the wheel all the way to the left and holding it for a couple minutes, then doing the same going in the right direction. So after a while of doing this the car will be quiet and no noise, but the problem is when I start driving or when I let the car sit, the car gets loud again. I checked to see if I'm leaking any fluid as this seems to be the most likely cause, but I don't see fluid leaking visibly. Maybe its a slow leak and air is getting back into the system? Either way I would really appreciate your help, thanks :)