So... I took my 03 Expy to a local Wal-Mart for an oil change a couple months ago. A couple days after getting the vehicle done, the power steering started acting weird.

By weird, I mean hard to turn. No matter what speed you're going, its pretty hard. Once you get the wheels turned either left or right from straight, it seems to be really easy again at highway speed until you have to turn the opposite direction, which again becomes hard til the wheels are past straight.

Okay, now I was heavily leaning toward the rack and pinion having a bad seal and basically causing the fluid to "fight" itself because it's going through the seal. I have to drive the vehicle almost daily, so I've been just dealing with it for a month or so. It doesn't seem to be getting any worse.

A week ago it through my mind for a loop about the rack and pinion... it miraculously worked perfect for 3 days straight. I could turn it dead stopped with 1 finger, just like new! Until I had to crank it all the way to get it out of a tight parking spot. As soon as I turned it all the way to the right it started doing the same thing again. I have it up on a ramp at the moment so I could just kinda peek around under there. Its hard to see well with the skid plate but I don't see any leakage at all. You can see the fluid moving in the reservoir with the vehicle running which makes me assume that the pump is at least pumping, even if not at full capacity.

What is weird though, I had my wife turn it just a little each way while it was running to see if maybe the steering shaft was binding or something simple. I didn't notice any binding, but I did hear a small whine when it was trying to turn a little.

OR is it possible for air to somehow get into the system and "air lock" the fluid in the rack and pinion? Maybe it had worked out after so long and cranking the wheel somehow it worked its way back in. Although I thought the reservoir acted almost a a vent and any air in the system should fin that to be the path of least resistance and escape out of it.

Sorry for all the chattering and questions, this problem strikes me as quite odd, mainly because of toe 3 days it worked great. Thanks for any comment of help you may have in advance

~James

I would suspect Walmart may have added the wrong fluid to the power steering system. Pep Boys accidentally put engine oil in a friend's car - I imagine because the fillers are right next to each other? I dunno. Seems like a really dumb mistake. It clogged up the power steering filter, which deprived the pump of fluid, and then both needed to be replaced. I drained the system (which is when I actually found the oil...), replaced the parts, and flushed it a couple times with the correct ATF. Works great now! If you have a filter on the Expedition I would check it for clogs, and then flush the system. Just remove the return hose from the reservoir and aim it into a bucket, put the nose in the air, then have a helper start the engine and slowly turn the wheels back and forth, pausing just before full stop in each direction. Add clean, new fluid as the old comes out. Stop when the fluid coming out runs clean. Replace the filter, and see how things are. Cost is about $20, and I'd say worth it before committing to serious repair.

[This message has been edited by thesameguy (edited 06-07-2013).]