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power steering problem

MjTjNJ

NAXJA Forum User
Location
Jersey
Hey guys,
I'm sorry in advance for this long post. I have a long standing problem that has stumped me and 2 mechanics. It may be just a "Jeep thing," that I'm hoping someone here has seen before. I have an 87 MJ with the 2.5. The PS reservoir is remote on this setup, with the serpentine belt/TBI. In the 15 or so years I've owned the Comanche, I had replaced every PS part over time, including the box, with a used ZJ fast-ratio box; the rest of the setup is bone stock.

A freaking YEAR ago, I had it out on a long trip, all highway. As I returned home, I heard the PS pump whine, pulling into the driveway. Got out, and PS fluid was pouring out the weep hole and around the cap of the reservoir.

I didn't know what happened, and I hadn't made any changes to the system in YEARS. Without thinking about it, I ordered a new ABS plastic reservoir from Crown, thinking it cracked or something. Replaced it, filled the system, went through the bleeding procedures, and same thing. Fluid everywhere, churning around the reservoir when I took the cap off to look. I then replaced all the PS hoses and O-rings. Same symptoms.

Wife was just about due with our daughter, I took it to a shop. Told me it was a bad PS pump, so I bought another reman, and they put it on. Said I got a bad reman, and so I found an OEM Chrysler one. I bought for the TBI engine, so rotation wasn't the issue. They then said "OK, must be the steering gear, it has some play, it's taking in air." Gave them my original box. Same thing. Gave them an OEM Chrysler ZJ box, same thing. They replaced all the O-rings.

The shop basically thought air was getting in somewhere, and took steps to stop that. Then they said it was a flow issue, and asked if there were supposed to be any filters/restrictors in the system, I told them no. They crimped my high pressure line in an attempt to slow flow (which only increased pressure). I know the owner at the shop well. He wasn't going to charge me if they couldn't fix it, so they had it for 6-8 months, working on it now and then, because it was a money loser for them. I finally took it back and had a friend who is a tech come and look at it. He found 300PSI at idle at the reservoir. He was baffled.

The ONLY hint I can give anyone -- aside from the fact that I have replaced everything twice -- is that during the bleeding process, wheels off the ground, when I get to FULL LEFT LOCK, and start slowly back to the right, you can feel/hear a "burp" in the system which will not go away. This has not changed with any new parts that have been thrown at the vehicle. Since the vehicle is not running, I'm guessing it's coming from the box.

When I drive it, which is almost never, I have assist. It's just noisy and there is fluid leaking out everywhere. Including the setup I had in place when the symptoms started, I've had three PS pumps, three gear boxes, two sets of hoses, two sets of O rings, and 2 reservoirs. Same symptoms. People have said maybe the pump is turning the wrong way, yeah but it had the same pump for years, and now 2 more. Others said that maybe the check valve is bad, but I've had 3 different pumps, the last 2 with new check valves on them (and I think the check valve only works in conditions of very high pressure).


ANY ideas would be appreciated. I'm disgusted, and would give the truck away if I didn't have so much sweat and money invested into it. I would pay someone in the NJ/PA area time and gas to fix it. Most shops don't deal in vehicles this old, and they're just going to begin replacing parts that have already been replaced.
Thanks for listening
Tom
 
Last edited:
What sort of setup does it have for the pressure regulator?
 
Sounds like some water got into the system and after it heats up it converts a bit of it to steam, blowing out the fluid.
 
I don't think, after replacing the entire system, there's any significant water in there. When the motor is ice cold, and I start it, it blows the fluid out. I don't know if the system EVER gets hot enough to create steam.
 
A couple thoughts:

Steam = air in essence, except water becoming vapor would expand more than air, if it were water in the system causing your problem. I tend to agree with you that its not water, though.

Bleeding the air from the system can take 60 or more turns lock to lock. Prior to bleeding mine recently I had read 30 turns would be sufficient, but after following that recommendation I still had the whine/noise. I ended up doing a couple of sessions where I quit counting at 60 before I got all of the air out. Just be careful not to crank the wheel so far that it "bounces" off the limits of rotation; I broke my clock spring that way.

Cap; did you replace your reservoir cap? The vent can become blocked and not allow pressure to be released as the system heats up and expansion occurs. I have had this issue cause leaking.
 
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