Was the pump the original issue? Or was it doing this previously as well. If it was doing this previously then it's probabl the steering box and not the pump. It could be a bad line as well. Did you use the proper fluid to fill it? If you only had the problem from putting in the pump, make sure to check to see if the belt is tight and correct fluid, filled correctly. Then turn with the engine running in each direction and try to work the air out of the system. You need to go lock to lock to do this. You may need to do this a couple of times.