Power Steering Problems When Hot!
 

Hey folks!

I've been hunting the internet trying to solve a problem with my power steering and I have been at a loss.

I had my engine replaced a few months ago with a shop over in Utah, and during the install they replaced my steering pump as the pulley wheel was quite bent (something I had been planning on doing myself, but always put off).

When I finally picked up my truck it was in the dead of winter with temperatures still floating around freezing--everything when it came to steering was working just fine.

However, as I returned back down to the desert, I have been noticing my power steering cuts out when the engine is well up to operating temperatures--cutting out and becoming still upon turns. When the engine is first turned on, and running for the first 20 odd minutes there is no issue at all with the power steering. For the life of me I have not been able to find the issue and really would like to avoid having to replace the pump.

To summarize:
-Power steering works fine ~20min on cold engine start.
-Once engine hits temps around 170-200F Power Steering intermediately cuts, especially around idle which I have set at 850rpm
-I have checked belt tension and replaced the fluid as I figured it might have been thinning out too much when hot. Issue still persists.

Anyone have any ideas as to this madness? Any suggestions would be helpful!

Re: Power Steering Problems When Hot!
 

Did they put the correct size of pulley back on when it was replaced? Air in the system?

Re: Power Steering Problems When Hot!
 

The pulley seems to be the same diameter as the one removed--and when checking the fluid after the engine has been running for ~30 minutes and is up to temp, there is no frothing in the fluid or bubbles to be found. I did change the fluid already to try and bleed out air using the steps in Haynes, but the problem still persists.

Re: Power Steering Problems When Hot!
 

I would guess that the pressure relief valve inside the pump may be sticking in the by pass position when the pump warms up. Thus you lose pressure to the steering box. You could get a test fitting and Tee it in on the pressure side to see check pressure both cold and warm. But be careful as steering pump pressures can go as high as 1500 psi. Its a pretty common thing in the rock crawler crowd to tear into the pumps and modify them for more pressure. I believe ours are in the 8-900 psi range.

Re: Power Steering Problems When Hot!
 

A trick i learned going to auto tech school in the 70's was to take a bright colored crayon and put a line on the face of the ps pulley. One line from the center to the outer edge, like a bicycle spoke. Now once it's warmed up have someone else turn the steering wheel back and forth and watch the line change rotational speed. Belts can slip but not squeel. Then you can compare the rotational image warm compared to cold.

Optical illusion can play into the image, and you can try running the engine at a fast idle and watch the image again. After a while it will make sense.

Re: Power Steering Problems When Hot!
 

This is something I was considering--I use this 'burb as an overlander off roader w/ a lift and 35's on her. Are there kits out there for this? In the meantime, I'll take a look at the pressure relief valve and see whats going on there and report back.

That's a good idea to try right quick. That was one of my initial ideas that the belt could be slipping when warm along with the fluid getting too thin. I'll try it this weekend and report back.

Re: Power Steering Problems When Hot!
 

My understanding of it is a tear down and shim removal and or drill out a restrictor. Depending on what pump and what it came off of. The all the information I got was from the Pirate 4x4 site some years back. I decided on sticking with my manual box and tall skinny tires.