Ford Repair: I have a 98 ford explorer..., lower ball joints, ford explorer sport

Question
I have a 98 ford explorer sport SOHC 4WD with 131,000

I have a noise coming from the front end when I turn my steering wheel from left to right. This past winter when it was cooled I started my car and had a hard time turning the wheel. I had to let the car run just for 20 sec till I could turn the steering wheel freely. Plus there was a squealing coming from the front. The serpentine  belt is not that old. I think it the power steering pump that is causing my problems. There are no leaks. I just think the pump is not working very good. What do you think?
Should I use a new ford pump at 170 or a remanufactured at $50 - $80. Should I also replace the lines and put a filter on?
I have just changed the tie rods and in the past 1 1/2 years I have had new lower ball joints, passenger side upper ball joint and wheel hub assembly.
About 3 years ago a mechanic said he thinks I will need a new rack & pinion when he did a bake job for me. How would I check the rack to see if that is making the noise?

Thank you for your help


steve

Answer
Steve, if it comes down to needing a new pump, the remanufactured pump is likely the better value.  They are a relatively simple design and have been rebuilt by companies for years.  However, before you decide to buy a pump you should have a specialist run some tests on the system.  
It could be that the rack is internally plugged, causing the pump to build excessive pressure before the assist ever starts.  Look at the fluid - is it contaminated with metal particles, or is it clean, pink fluid?  If contaminated, you will need to flush the system well whenever a component is replaced to avoid damaging the new component(s).
Hope this helps, but there are not easy tests to make.  A shop with a power steering analyzer is needed.
Clay