I need help troubleshooting power steering

Hey guys,
I have a 1990. 4.0, 5-speed (if it matters) and am having an intermittent power steering problem.
It started during the summer when you could occasionally feel additional resistance to turning the wheel. It was so mild, that you could almost convince yourself that it wasn't there or that the road was causing it. So I decided to wait and see if the symptom became more distinct and it hasn't dissapointed me!
Now, 1/2 the time it turns with no effort, the other half of the time, it is very difficult to turn! When it is tight, it's hard to be sure but some spots in the revolution may be harder than others, which leads me to believe that it might just be the u-joint in the steering shaft. Ohter times I'm not so sure, and the steering box does now have a slow leak when the steering shaft enters leading me to think that it is the box, but then I think that if the u-joint is binding, it may be putting an unnatural side load on the shaft causing it to leak?
How do I trouble shoot this? How hard is it to put a new box and or steering u-joint in? Could the pump play a part in this?
Thanks!

I had a similar thing happen once on a ford cargo - turned out to be low fluid levels brought on by leaky hoses. I just popped on a new set of hoses and haven't had a problem since. Check your dipstick first!

Perhaps it's the PS pump itself? I recently replaced my ps pump with a Napa reman one. It steered fine for the most part, except from a dead stop turn. Parallel parking was horrible. It was a bitch to turn, until I was able to roll the vechicle a little.

I replaced the one day old reman PS pump with another, and the hard turning disappeared. I must have got a bad pump. That's what makes me wonder about your PS pump perhaps about to give up the ghost...

Ivan

I'm open to all ideas/theories, what's mosy perplexing to me is that it comes and goes. I'm definitely hoping someone reads this that has had the exact same symptoms!

Check the valve under the high pressure hose coming out of the pump. My 97 would get hard to turn at about 3/4 turn and the dealer couldn't figure it out. While I was rerouting/replacing the hose I noticed it, pulled it out and found the center part had unscrewed ever so slightly. Tightened it back in and it never did it again. It has a ball bearing and spring inside and I'm pretty sure it's meant to prevent fluid from going the wrong direction.

As for replacing the box it's not that difficult. I just did it about two days ago I was taking my time and it took about 2hrs. Good luck!

Thanks for your responses guys. I realize the things it could be but am hoping for some help in troubleshooting the problem so that I don't replace everything! I can't be the only one to ever have power steering problems am I?
As far as the pump goes, my experience with pumps is that they either pump or they don't, what kind of intermittent problem could it have? I'm thinking it's the box as I assume there are valves and such in there that might come and go, thoughts? And of course I keep looking at that little u-joint in the column, do those ever go bad?
It's cold and snowy here in NH, I don't have a garage, and Christmas is coming (i.e., no money!) HELP!

Ok, assuming I go the easy way?? and buy a used box/pump/shaft out of a yard, what years will fit my 90?
Thanks,
Scott

I feel sure it isn't the shaft, and is probably not the pump. Make sure the fluid level is full before anything. It is probably the steering box. It has a pressure valve that opens in either direction to provide boost to the right or left, and that valve is probably bad. Get a box from a junkyard. You can get one from any XJ, or a 93-98 Grand Cherokee. I got one from a 98 GC, and it steers much better than my old XJ box.

Thanks Jack, yeah I've checked the fluid level all along. It wasn't leaking when I 1st detected the problem, but has started to now (it is full though).
Unless anyone has something to add, I guess I'll try to find one at a recycler. Is the GC box a "better" box, or is yours so nice because it is almost new?

see i have this problem too. but the times that it doesn't work well is when it is hot, like i have driven my XJ for a long time, and thats when it gets worse. anyone have anything on that????????

My YJ does that every now and then. Replacing the power steering pump in the past did not fix the problem. I've found that by hosing down the steering shaft U-joints with WD40, the problem disappears for a month or two. Now, one of my friends had a similar problem with his Jeep, and it turned out to be the steering box.

XJ_MAC, are you referring to the sensor-looking thing on the HP power steering hose? Since you have a 4.0L, it's probably not connected to anything. That sensor is actually designed to raise the RPMs of the engine, when at idle, if steered. There's a lot more load placed on the power steering pump when the wheels are turned if the vehicle is stationary, so that sensor was Chrysler's way of preventing the engine from stalling. It was only operational on the 2.5L four-cylinders... kinda gives you an idea of how little power those things have . My YJ is as slow as a dog.

Hey IROC, I decided to try lubing the u-joint from the outside since it worked for you, and guess what? It worked! I used foaming liquid wrench because it has some cling to it. Thanks for the help, now back to that fast idle that won't go away.......

iroc86 said:

XJ_MAC, are you referring to the sensor-looking thing on the HP power steering hose? Since you have a 4.0L, it's probably not connected to anything. That sensor is actually designed to raise the RPMs of the engine, when at idle, if steered. There's a lot more load placed on the power steering pump when the wheels are turned if the vehicle is stationary, so that sensor was Chrysler's way of preventing the engine from stalling. It was only operational on the 2.5L four-cylinders... kinda gives you an idea of how little power those things have . My YJ is as slow as a dog.

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NO, its actually an in-line valve in the pump. You need to remove the high pressure hose at the pump and then it unscrews out of where the hose fitting goes in there. Has a screw driver slot in it, if I remember correctly. Its been a couple years since I fixed it.

Scott, glad to hear that you fixed the problem! I've been meaning to buy a new steering shaft for my YJ, because I've read that the factory U-joints in the shaft are not serviceable or replaceable. A few sprays of a $2.00 lubricant every month is lot cheaper than a $250+ steering shaft, so I'm in no hurry . I'll have to try Liquid Wrench the next time.

XJ_MAC, now I see what you're referring to. I never bothered to take a pump apart, but that sure would be an elusive problem if you didn't already know to look there.