I have a 91 F350 4x4 with the 7.5. When I bought the truck, the guy told me the power steering pump was bad. I changed the pump, went through the bleed procedure. Nothing. I hear the pump running. It just has no assist to turning at all. Drained the power steering fluid, tried type F tranny fluid, and still nothing. Even jacked up the front end, tires will turn, but still no assist. It has the vacuum style pump. Any ideas why Im not getting any assist at all?

 

Do you have a blockage in the lines?

 

I dont think so, I flushed them when I changed the pump.

 

Did it work properly when you bought it?

 

No, the guy told me the ps pump was out. I figured it would be a pretty easy fix.

 

Is there something in the steering gear box that would inhibit the power assist, but still let me turn the wheels freely?

 

Yep… but I'm no steering box expert. Looks like a new/used box is in your future.

 

Thanks, I was afraid of that. Just kinda wanted an idea before I start throwing parts at it.

 

To check to see if the line is blocked, can I just unhook the low pressure hose from the pump, crank the engine? Fluid should squirt out of there?

 

the high pressure side does the assist. I would pull the lines off and blow them out with a air compressor. if that dont work mix some Marvel Mystery oil with the fluid and let it run for 5 or so minutes then drain and put fresh fluid, If that dont work replace it.

 

Im starting to wonder if the high pressure line ever compresses itself enough to not let fluid pass?

 

Can't you see fluid circulating in the reservoir?
If a line was blocked (I can't see how, under that pressure ) there would be nothing coming from the return line and the noise from the pump would be unbelievable.
Maybe it's just time for a sector box?

 

Theres just the normal hum coming from the pump. Cant really tell if the fluid is moving in the resivoir or not. When I get some time, Ill try a new box and see what happens. Just trying to avoid it unless I have to.

 

If the high side line was plugged the pump,would be squealing like a pig under a gate. Pull the return line and plug the return port on the pump housing just hold the return line over the filler housing run the engine and see if it moves fluid. I have seen new / reman pumps that where bad right out of the box.

 

I picked up a steering box today, going to try and get it in the next few days and see if that helps anything.