Power steering stiffens up when truck warms up

[96-2D-Hoe]

I have a reman PS box, that when the truck starts from cold is incredibly light. But when the trick gets hot, and/or the AC has been on a while, most of the time when I stop to park the steering is very stiff.

Any ideas?

 

[OR VietVet]

Could be a faulty box but remember that the box reacts to pressure provided by the power steering pump. Likely have a pump problem and when you do it, replace the lines/hoses too. Use power steering fluid and not trans fluid. Bleed the system correctly as well. What brand box did you install?


What I recommend as steps for refilling and bleeding air out of power steering system.


Raise front tires off the ground. Fill fluid and with engine off, turn stop to stop slowly and add fluid as needed. Turn stop to stop again and again fill as needed. I recommend doing this at least three times before dropping the vehicle back to the ground. Then start the engine and add fluid as needed. Turn wheels stop to stop slowly. Refill as needed and turn stop to stop until you do not have to add fluid. Then roadtest at least one time, I always do it twice, and top off fluid as needed. Check for leaks.

 

[96-2D-Hoe]

Was, flushed a bit, properly bled and new fluid. No lines replaced or pump replaced. Been on a couple years but it's pretty much always done it. I don't drive far often and so the truck doesn't often get up to full temp. It's not been much of a problem but it's annoying. Fluid looks fine.

Could it be the highway thing that reduces the pump pressure not working properly?

 

[exp500]

Does your P/S Pump have the EVO valve on the pressure line? ( wires connect to it, on rear of pump). Otherwise, your pump is failing if a flush doesn't fix it.

 

[OR VietVet]

No. I would say you got a bad box from the get go. At this point I would replace both and the lines/hoses and see if the box is a warranty item. But, remember that I love to spend other people's money so if you want, just do another box.

 

[96-2D-Hoe]

Thanks for the replies.
I didn't have the issue with the previous steering box and so I've not thought the pump very likely. I haven't noticed any wires but I will check. And as for swapping it out again, I'll hold off on that thought until I'm 100% certain.

 

[exp500]

Why did you change the Steering Box? Did I miss previous posting about this? More info please. I was leaning towards a reverse malfuction in the EVO system, Or pump output pressure low.

 

[96-2D-Hoe]

No EVO wiring I can see.

Box was changed because it was leaking from the pitman shaft. Was installed early last year with a LARES 1417 Remanufactured. Fluid is still clean and truck has done around 2k miles since.

What I don't get about it being the pump is why it's only happening when hot, and it works perfectly when cold/warm. Just the hotter/thinner fluid?


Thanks for the help.

 

[OR VietVet]

That is why I said to replace the lines/hoses at the same time. One other thing, how does the belt look? Is the hose kinked or bent instead of being routed for full flow? Power steering fluid or trans fluid?

 

[OR VietVet]

Does it have a power steering cooler on it? If so, check for restricted air flow.

 

[96-2D-Hoe]

No cooler.
No trans fluid.

I just thought to call Lares and the guy said it could still be a little air in the system. Or otherwise lean toward a new pump.

He has told me to try a bleed procedure where I lift the wheels, discon fuel pump so no start, and start steering wheel in center and slowly move steering out left to right a little at a time while cranking engine over, until I finally get to full lock either way. Obviously not cranking for too long so I don't burn out the starter and checking for foam or bubbles.

I'll give that a go today/ASAP.

Thanks for the help. I'll report back.

 

[OR VietVet]

If that box was put on almost 2 years ago, there is no air in there.

 

[exp500]

That pretty much narrows it down to the pump. Did Lares comment on recommended fluid? I've had 100 Percent success with their rebuilds. It is a vane style pump, so likely bypassing/leaking inside when hot thin fluid used.

 

[96-2D-Hoe]

Thanks for the replies.
Been on for just over a year but hardly any miles. No mention of fluid. I'll try the bleed for the hell of it. Easier than the other options.

 

[96-2D-Hoe]

I just drove 5 miles to get some brake fluid to do my rear brakes. It's 80+ outside but steering was already getting stiff when I got home. Fluid was very hot, but no sign of air/foam in fluid.

Here's my shopping cart. Unless anyone has any better recommendations? No Delco parts available at RA.



PS.
Happy 4th everyone

 

[OR VietVet]

I think you are on the right track but since you said you have had the problem for close to 2 years, since you put the new box on, I still feel there is a suspect problem there.

 

[96-2D-Hoe]

Flushing the fluid has definitely helped a fair amount. I think I may have had this issue to a similar degree before I got fussy after I changed the box and all the steering components. But I had let it get to the point where it was kind of dangerous to drive. Not helped by a ******, lazy mechanic.
PS pump was last replaced under factory warranty apparently for leaking in 2001. It seems acceptable for the moment but it wasn't a very hot day today. PS pump replacement is in my future, along with all the other things I'd like to do. Thanks for the help.