Steering locks up at idle...

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Mar 21, 2011 | 09:58 PM

Myfreeford

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Steering locks up at idle...

75 F250 2wd, 460, A/T, power steering

I just installed a new steering gear box on my truck and am experiencing an issue where the wheel will stop turning - like it is hitting something - after the truck warms up. This only happens when I am sitting at an idle. If I am accelerating in gear or even in park, I can turn the wheel all the way both directions without any issues at all. It is like the pump is losing pressure until the motor is turning faster. I installed a new power steering pump about a month ago and did not have any problems until I finished installing the steering box.

I did notice that it is slightly moist around the pressure line where it connects to the gear box. It looks like a small amount of fluid comes out between the threaded fitting and the metal line. Would this mean that the flaired end is not seated properly where it fits into the box? If so, would just a small amount of fluid coming out cause a loss in pressue and cause the wheel to lock up like it does?

And, what about the p/s pump cap - I did not replace it when I did the pump - is it possible that it is loosing pressure thru the cap?

Thanks for any assistance.
Chris

Mar 22, 2011 | 08:41 AM

fmc400

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Joined: Apr 2004

Posts: 10,386

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From: Austin, TX

The leak is because the flare is not properly seated as you suspect, but it shouldn't keep the box from working if it's just a slow seep. Tighten it up anyways.

The only thing I can think of, is maybe there is some sort of blockage or restriction in the box that is keeping fluid from flowing when pressure from the pump is at its lowest. My understanding is that the pump output is supposed to be somewhat regulated (so it doesn't blast out the box at high RPM), but I imagine there is some dropoff at idle. If the system worked fine until you changed the box, I'd suspect the box unless someone else has any brighter ideas.

The PS pump cap won't be related to the issue; it's just to close off the reservoir. There is no pressure against it. If you open it up with the engine running, you'll just see the fluid sitting there. When I replaced my box, pump, and lines a while back, I kept the old cap. No point in replacing it if it's keeping the elements out of the fluid.

Mar 22, 2011 | 09:00 AM

jjski78

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Do you have a filter in your return hose? If so it may be partially clogged where it gets enough pressure for fluid to go through with the RPMs above idle, but at idle it's enough of a blockage to stop the flow. This is kind of a weird problem I've never seen before on any vehicle. Even if there's air in the system it will work, it'll just make a lot of noise doing it. I would start cheap and replace the hoses and the return line filter. Refill the system, bleed off the air, and see if it fixes it. Just my .02 from experience on other vehicles. I'm kinda new to the whole American Iron thing.

Mar 24, 2011 | 09:27 PM

Myfreeford

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Quote:

The leak is because the flare is not properly seated as you suspect, but it shouldn't keep the box from working if it's just a slow seep. Tighten it up anyways.

Well, I tried seating the flaired end again and still a small leak. After talking to the guys at Napa, it seems that it is possible that the steering gear box is the issue. So, I get the privilage of pulling it out again to exchange for another one. But, now that I have done it, I know what to do and not to do...so the job will not be so bad.

Quote:

The only thing I can think of, is maybe there is some sort of blockage or restriction in the box that is keeping fluid from flowing when pressure from the pump is at its lowest. My understanding is that the pump output is supposed to be somewhat regulated (so it doesn't blast out the box at high RPM), but I imagine there is some dropoff at idle. If the system worked fine until you changed the box, I'd suspect the box unless someone else has any brighter ideas.

Well, I took the power steering pump out, installed a new one and problem solved. No more steering locking up.

Quote:

The PS pump cap won't be related to the issue; it's just to close off the reservoir. There is no pressure against it. If you open it up with the engine running, you'll just see the fluid sitting there. When I replaced my box, pump, and lines a while back, I kept the old cap. No point in replacing it if it's keeping the elements out of the fluid.

Good to know - this is one of the little things that I wondered about.

Quote:

Originally Posted by jjski78

Resolved the issue with the steering locking up. But, I do not have a filter in the return hose. Should I have one? I decided against one at the time of installing the new steering box...not sure why - I guess I was not sure if it was really necessary.

Thanks for the suggestions - funny how it can be so frustraing when something is wrong and you don't know what...but once it is fixed, you feel kind of like a god...HAHAHA!

Mar 24, 2011 | 10:20 PM

lonnie1952

Senior User

Joined: Aug 2010

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From: Moreno Valley

Quote:

Originally Posted by Myfreeford

75 F250 2wd, 460, A/T, power steering

And, what about the p/s pump cap - I did not replace it when I did the pump - is it possible that it is loosing pressure thru the cap?

Thanks for any assistance.
Chris

The power steering pump can bind up causing steering lock-up
Been there done that...Check it to be safe

Mar 25, 2011 | 12:46 PM

jjski78

Tuned

Joined: Mar 2011

Posts: 320

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Quote:

Originally Posted by Myfreeford

I would put a filter in the return line. Especially if you didn't change hoses. Keeps any particles from the deteriorating hose from getting into the pump.