need help with p/s

SEE SAFETY ISSUE..

There are two bolts, one on either side of the fitting that the top PS hose attaches to, those bolts need to be loosened slightly, and that fitting needs to be gently tapped either forward or back. You're looking for the sweet spot where the steering wheel doesn't want to move left or right.

If the vehicle pulls to the left,, the fitting needs to be tapped forward..
If the vehicle pulls to the right,, the fitting needs to be tapped rearward...

Don't loosen the bolts too much,, or let it hit either stop hard, or you may blow out an o-ring..

Personally, I prefer the front wheels off the ground..

SAFETY ISSUE Don't put your arm thru the steering wheel to start the engine, as the steering wheel CAN slam over hard and cause injury,, serious injury could occur..

From FSManual..

Start engine. If unit is self-steering tap valve
up or down to correct. When tapping valve ""down,"
hit valve body on end plug. When tapping valve '"up,"
tap on head of screw attaching the valve body to
main valve body. Do not hit control valve body.
CAUTION: Do not turn hard against ends of travel.
This will generate high pressure and may blow out
the ""0rin gs since the valve body screws have not
been finally tightened.
(20) With steering wheel in straight ahead center
position, start and stop the engine several times, tapping
the valve body up or down as required until
there is no movement of the steering wheel when the
engine is both started or stopped.
(21) The valve is now centered. Tighten the two
screws attaching valve

hope it helps