Not sure wher the resevoir is on skyline Dan, but if its away from the pump it may be same as problem i had with Supra before,
At the bottom of resevoir, there was a pipe coming out and feeding the pump, inside the resevoir there was a mesh filter, almost like a siv, they are prone to get coverover in gunk and restrict the fluid getting to pump, so you have no power steering at points or at all, and you get a noise like its empty or low on fluid as when its blocked its essentially the same as no or low fluid level..
Again maybe skyline is different but i think they are the same set up
If its same, take out fluid, and clean the mesh with screw driver rapped in cloth etc etc, the mesh could well be a false bottom in resevoir, so could be completly coverd, be carefull not to puncture it, if you do clean it, be good idea to give her fresh fluid aswell.
There maybe other ways to do it on the Skyline, on Supra it was above method or buy a new resevoir which most do, but im a cheap fooker