on all my w-bodies: my current gp, my old gp, as well as my old regal, I had the same problem. The regal had a small hole wore in one of the rubber PS lines, but wouldn't leak fast enough to get on the ground- just would drip off when I was moving. I replaced it with one off a j/y regal. The old GP had a leaky rack, which I just put up with until i sold it. The current gp, on the other hand, leaks from the bottom of the pump... which I havn't gotten around to replacing yet. From j/y'ing, i have seen many w-bodies with leaky racks. FWIW, i used some of that leak stop in the old GP, and it slowed the leak down considerably.
hope this helps