Diagnosing power steering: Rack, pump, both, or neither?

[coco-puff]

Tried searching but there are too many threads related to power steering so I hope you guys don't mind me making another thread.

My 1992 is leaking PS...badly. I have power steering only every once in a while. I'm not too worried about it but I would like to get around fixing it eventually.

I am guessing the rack needs to be replaced instead of the pump but is there a way to diagnose if I need a new rack or pump? I don't want to fix one and the other one be the root of the problem.