In Reply to: Power steering on a 641 w/ Wagner 3 loader posted by LeRoy on September 04, 2024 at 00:06:42:
Keep in mind that the original ps pump operated at about 700 psi. So I wouldn't go much higher.
On the 1965+ 2000/3000 three cylinder Fords the PS setup is nearly identical to the pre 65 Fords. On the larger tractors 4000/5000 the same ps pump is used but the pressure is set at 1100 psi.
There have been many posts on yesterdays tractors forum about guys bending the rods in the steering cylinders after replacing the the steering pump. The culprit was found to be they installed an 1100 psi pump instead of the 700 psi pump.
I would not increase your pressure by very much.