p/s 92 K1500 Pickup?

Ok,

Here's my problem. I'm having an issue with the power steering being hard to steer at an idle once the truck is fully warmed up.

Truck is stock with 350 engine, I've replaced the OEM P/s pump with a GM rebuilt pump...same problem. At times when the truck is at operating temp, the steering is hard to turn at idle. You hear some pump "whine" and its hard to turn. If you increase rpm a little bit truck steers normal.

Truck is full of P/S fluid and has no issues that I'm aware of.

I then replaced the GM rebuild pump with another from the dealer under their parts warranty. Same exact problem. I then replaced that p/s pump with one from AGR. (I think that's the correct brand name). Same problem but not as bad.

The only thing to look at now is the P/S gear...but the whole thing just really aggravates me. It still sounds to me like its a pump problem since the steering will function properly if you increase the idle speed by a couple hundred RPM.

Anyone have experience with symptoms of a bad P/S gear, because that's the only thing I've not replaced at this point.

Local GM shop has run out of ideas...they want to blame the tires (

285 75 / 16 BFG AT Radials ). But I don't see it that way because the truck steered fine with the OEM pump and the same tires. I initially replaced the pump because the fluid looking like a brown mess when I got around to looking closely at it , and its bitten me in the @ss ever since.

More info... I think the truck idles around 500 RPM, don't know if that the correct idle speed, my buddy at the GM dealer made no mention of a low idle.

Any thoughts? Truck has new p/s hoses and so the only item left is the p/s gear..

Elbert

----------- Elbert snipped-for-privacy@me.com

Reply to
Elbert
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Are you talking about turning the wheels with the truck stopped or rolling?

Al

Reply to
Big Al

Pumps really do not fail that much (usually they leak or get noisy but still work) YOu problem is in the steering box/gears and what is likely happening is that it has a leaky seal of control boost valve in it that does not leak much when it is cold and then with fluid warms up and thins out it "leaks" to the point that it does not provide enough boost assit. The noise the pump makes when turning is from fluid flow and is normal.

----------------- TheSnoMan.com

Reply to
SnoMan

I'm talking about at a dead stop. And I don't mean that the effort just increases a little bit, I mean sometimes you can't turn the steering wheel but just a little bit and that's all it will do without increasing the engine RPM.

Its certainly not normal. You would encounter this when parking or at slow speeds when you are maybe off road and having to go slow.

Elbert

----------- Elbert snipped-for-privacy@me.com

Reply to
Elbert

Thanks... seems to make sense. I did not want to go through the trouble of replacing the P/s gear and still have this problem, but there's only one other component in the loop now to look at.

You ever run a fluid cooler on your P/S system? I would think on a 4 wheel drive the p/s system has more mass to move thus most likely generates more heat.

Elbert

----------- Elbert snipped-for-privacy@me.com

Reply to
Elbert

Steering boxes do get "tired" on 4x4's

Most HD GM 4x4's have them in the form of a a length of tubing on the bottom of radiator shroud. My 4x4 V1500 burb and 2000 K3500 has them. ( I bought them both new so them came that way)

----------------- TheSnoMan.com

Reply to
SnoMan

I would be more noticeable at lower RPM's when there is less flow to overcome interanl leakage in steering box.

----------------- TheSnoMan.com

Reply to
SnoMan

It's normal if you have oversize tires. On some GM trucks if you step on the brakes real hard you can't turn the steering wheel because the power steering will bypass to keep from damaging parts.

Al

Reply to
Big Al

Maybe on a 9200 GVW or higher truck or one with a diesel because all others use vacum power assist for brakes. My 2000 K3500 has hydraulic boost and I cannot every remeber a time when there was no sterring boost when braking and truning while plowing snow which can put a lot of weight on front axle. If you have issue with this is is because you are approaching the design boost limits of steering box, not because your are braking too because the system design takes this into consideration and should work normally with stock or near stock loads.

----------------- TheSnoMan.com

Reply to
SnoMan

Al,

I agree with some of your points. But on a 92 1/2 ton pickup there are no sensors in the P/S system so the truck basically runs the "old-school" type of plain jane (pump + sector) no electronics.

While I do consider the 285 75 R 16 tire larger than stock, its my own belief that this is not the problem. Because I ran the same tire combination for the last couple of years and the pump I had initially performed fine and I never experienced this previously. I would agree that the tires may be a contributing factor to this issue.

I plan on swapping out the p/s gear and looking around to see if I can find a OEM P/s cooler setup.... If I can't then I'll most likely plump in an aftermarket one.

Elbert

----------- Elbert snipped-for-privacy@me.com

Reply to
Elbert

I may look around and see what I can find out about adapting one of the coolers of a 3/4 ton or 1 ton truck. I've seen those before, but its been many years ago when I played mechanic. I still like to screw around with my own junk.

How does your truck (with the ps cooler) route the fluid over to the cooler? Is there a barbed or other type fitting on the low side of the gear and a hose run over to the cooler pipe? That's what's on my Yota land cruiser. I would like to round up the parts off a GM truck so that it would look "clean". We'll see what I can find. I do know that a number of companies make various type coolers. I more concerned with finding the right type of fitting / adapter to run from the P/S gear + rubber hose + cooler........then back to the pump.

The only adapting I see is finding the right fitting to mate to the P/S gear.

----------- Elbert snipped-for-privacy@me.com

Reply to
Elbert

what year model is the suburban....so I can use as a parts reference

----------- Elbert snipped-for-privacy@me.com

Reply to
Elbert

It is a 89 4x4 1/2 ton suburban (V1500) with a factory HD towing package. It also has a factory external aux engine oil cooler.

----------------- TheSnoMan.com

Reply to
SnoMan

There is a bypass in the power steering pump. Get a service manual and look. If you were to park with the front wheel against a curb and turn the steering wheel and there was no bypass you would bend parts or blow hoses. Just think about what's going on there.

Al

Reply to
Big Al

-

When he changed the pump, he changed the bypass because it is part of it. Steering boxes do fail and oversized tires to accelerate the process some (the bigger the tire, the more average strain on the steering box) Some one to hold out false hope though. BTW, there is a flow control valve in steering box too.

----------------- TheSnoMan.com

Reply to
SnoMan

No one said the bypass was bad. It's there to protect the system. You claim to have a service manual, read it.

Al

Reply to
Big Al

No need to I have and I have seen bad steering boxes too. THis poster has a steering box issue not a pump issue. My 79 J20 Jeep truck has a bad steering box in it (and it uses a GM one too) as the result of years of pushing snow with erratic boost at times. When I restore the vehicle it will get a new/rebuilt steering box.

----------------- TheSnoMan.com

Reply to
SnoMan

Ok ,

I came across this on Ebay.... where does this mount. This specific p/s cooler is off a 03 GM 4*4 pickup. I assume somewhere around the bottom of the radiator support?

I'll try and attach a picture to this msg of the cooler.

----------- Elbert snipped-for-privacy@me.com

Reply to
Elbert

That is serious cooler, bigger than mine. You would want to mount it in the air flow in front of radiator vertically on drivers side but you may want to cover it up some in winter to prevent stiff steering from over cooling of oil.

----------------- TheSnoMan.com

Reply to
SnoMan

what's the logic of mounting the cooler vertically? I have seen a P/s cooler mounted on a Ford 2 ton truck that was mounted in that fashion, but have never bothered to ask why this was done.

I'll get my buddy to look on the GM (on-line manuals) to see how this cooler was installed on the 03 pickup. The dealer guys have access to shop manuals on-line (Internet / computer) back to 1998 or so.....

Seems like in the vertical position all the fluid will drain back into the reservoir when truck is off. This may be the issue... I do know that the low side pressure on the p/s pump is not to great. I've also seen models like my Toyota land cruiser that has basically a length of plain jane steel tubing for a cooler and it runs horizontal.

----------- Elbert snipped-for-privacy@me.com

Reply to
Elbert

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