So my 1989 F350 Diesel is supposed to have power steering.

On the Highway, I can never tell if it's out or not. Steering effort is easy.

When turning at low speeds or stopped, I can tell.

Sometimes, I can feel that it's working properly, others I know it's completely out and I think I'm going to break the u-joints in the column turning that wheel.

Should I look to the pump or gearbox first? Fluid is full.



The money I've saved in Gym membership will go to paying for
parts.

 

If it seems to happen at the same spots or works best for the first few degrees of steering, I'd highly suspect the gear box. If it just doesn't turn at low rpms then replace the pump.

 

I would first drain and flush the old oil and put in some new high quality oil. most peple never change the fluid in there P.S. and then they wonder why it gets noisy and or the system quits all together.

 

You might want to replace those hoses as well.