Jeep Cherokee Forum - Power steering comes and goes on my 98 GC

A year-and-a-half ago, the power steering pump spectacularly ripped the middle out of the pulley and threw it out the bottom of my 98 Grand Cherokee 5.9. Since then I replaced the pulley, pump, steering gear, belt, hoses, and all the steering components down to the wheels. I even installed a power steering fluid filter on the return line. All of those parts came from Rock Auto.

Prior to that I replaced a leaky water pump, and read instructions that said pay no attention if it whines on installation, because it just needs to be broken in. So I didn't heed the whine under my hood when I replaced the power steering components. It wasn't that loud, and I just thought it was still the water pump being a little slow quieting down. Recently it got way worse, so I replaced the A/C clutch, which did have a wobbly bearing. Wrong item. A big, rapidly-getting-scarier whine remained. I'm now on my 4th new power steering pump. Pump #2 from Advance didn't come with new o-rings, and I didn't read the directions that said "don't hammer the pulley onto the pump" until after I had already given it a few good whacks. Yeah, it whined on start-up, so back to the store it went.

Pump #3 from Advance also whined, so I took it to NAPA and bought a new one there. With Pump #4 installed, my Jeep has developed the disconcerting habit of disappearing power steering assist. Apparently once it's run a bit, and especially on the highway, the power steering just goes away. It seems to be heat-related, as it comes back when the vehicle cools off. I just drove it 15 miles, and the power steering pump was very, very hot to the touch when I lifted the hood on arrival. Oh, and it whines, too, just like the Rock Auto pump did when new.

What am I missing? When the power steering works, it seems just fine. I did have to go through a couple of steering gears, because 1 or 2 of them dragged on installation, but this one is fine.

Thomas