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?

 

Did you bleed pump while truck was in the air turning wheel from Lock to lock? You may still have air in the system.

 

I've tried that a couple of times. With the engine off, then with the engine running. I can hear the pump hum, there's just no assist whatsoever.

 

Getting the air out of the system is critical with these. Patience pays. Last but not least you won't be the first to have a defective aftermarket pump. OEM pump assys usually work the first time when installed. For some reason a lot of aftermarket pumps come with problems.

Did you use the proper tools to change the pulley ? If not, pump could be damaged internally.

 

something tells me that it ain't the pump when the old went bad it may have sent shavings all through the system and now that a new pump has installed it may be a bad gear box. we all hope that's not it. and make sure there's vaccume leaks either

 

I picked up a steering box, Ill go ahead and change it out when I find a little time. I cant imagine it could be anything else.

 

I have never seen a vacuum type P/S pump on a ford truck. Are you sure this is not a hydroboost system?

 

A different steering box seemed to fix it.

 

that depends on how much metal went through it. glad you got it fixed for now