D-14 power steering

Recently put AC power steering unit on non power steering tractor. Unit was from a dead in water loader D-14, I hadn't driven it, so didn't know if in working order - guess what, doesn't have any steering assist at all. Any suggestions as to where to start trouble shooting? I did replace the complete bolster and engine from dead in water tractor. Thanks for any help / suggestions.

Went through this same thing last year on my non PS D14. There is a thread on here about my venture. Long story short, 2 things caused my new to me PS and bolster not to work that came out of a non running tractor. First thing was that I had soaked all the lines in my parts tank letting them soak for about an hour to loosen any crud that may be in the lines. My first mistake was after removing them from the tank I laid them on a towel to blow them out, blew 2 of them out. Went in the house to get a bite to eat and forgot to blow out the suction line! That bites me later on. After I put everything on the tractor I started it and the disappointment of no PS hit me. What did I miss? Dr Allis told me to try to prime the pump which I did by removing the suction tube. Only so much oil will stay in the pump because the pipe enters from the side. Started the tractor and still no PS. Took the suction tube off to try to put more oil in. But this time I pulled the coil wire off and turned the engine over, guess what, the gears in the pump were not turning. So I pulled the pump and began to disassemble. Found the drive shaft was missing the drive pin! No way it could have come out. Got a new pin, put the pump in, turned the engine over and the gears were turning inside the pump. Didn’t make sense at first why it was missing but hey I was happy. Primed it, installed the suction tube. Install the coil wire, engine fired up….no PS. What the heck??? Removed the suction to investigate and bam it hit me, I never blew out the suction tube. Took it over to the trash can and after a couple good burst of air a big blob of crap blew out of the tube. Really cleaned the pipe out well again in the tank. It was stopped up so the pump couldn’t suck any oil into the pump. Primed the pump, reinstalled the suction tube, fired up her up and bingo I had PS. So my guess is the owner started having PS problems and then no PS. So to prevent pump damage maybe he removed the driveshaft pin??? I have no idea, only a theory. Sorry for the long thread, but that was my issues.