Power Steering Issue

[XWrench3]

So my daughters KJ has developed a power steering pump issue. I think it may be related to the very recent extreme cold weather that we just had. She went out to go into town, and she came right back into the house saying that her truck was making a TERRIBLE noise. So, I went out to listen to it (at -6 degrees f. , that was ALL I was going to do), and I figured it was either the alternator ot the power steering pump. I have had both make horrid noises in sub zero weather in the past. I touched the alternator first, then the power steering pump. And it was obvious that the power steering pump was making the noise, and accompanying vibration. We closed the hood, and her boyfriend took her to town. I looked at it just now, and the fluid is quite aerated. What I thought was very odd, was that after approx. 2 minutes of run time, there was a LOT of air pressure inside the pump. enough that it nearly blew the cap out of my hand when I removed it. I have never had that happen in the 60 years of working on my own cars. I brought the cap in the house thinking that maybe there is a vent in it that is frozen. / Since we have no maintenance record on this truck except the last 9 months or so. And the fluid was pretty ugly looking, I thought we would do a "down and dirty" quick flush, and do it correctly when there isn't 8" of snow on the driveway. something that I found curious, was after removing as much fluid as I could with a turkey baster, and refilling it, I had her start the engine, and steer the wheels side to side then shut it off to repeat the process. I kept a tight fitting funnel in the fluid fill opening of the pump. and after that short amount of time, the fluid had pushed its way half way to the top of the funnel after it was turned off. So the fluid is being pumped FULL of air somehow. I have never been inside of a p.s. pump, so i have no idea how they function. Does she need a new pump? or is there ice in it someplace (she does do a LOT of short trips) that a nice 50 mile trip will melt, retuning the pump to its proper function? I guess I have been lucky, as in all of these years, I have only had to replace one rack in a p.s. system. And I had to have 1 high pressure hose replaced, because I had just had surgery, and I could not do it myself. I have changed the p.s. fluid in most of my vehicles, but that is all that I have ever had to do.

 

[KJowner]

Is the suction line split or loose? Failing that I'd guess a seal has gone letting it draw air in. They are usually only a simple vain pump, no idea if a seal kit is available though.

 

[LibertyTC]

Get Jeep well warmed up first.
The KJ OEM spec uses RED ATF+4 automatic transmission fluid in the power steering pump.
Suction out the pump reservoir & start over. Front of pump has a full line indicator.
If pump is very noisy, jack up the front of the Jeep, and move wheels back & forth to bleed air away in the system.