1958 Skyliner power steering reservoir cover

[droptopford]

The day I checked out the cover on my power steering reservoir, I noticed that the fluid looked pretty dirty. Not surprising really; I would bet that most of that fluid was 60+ years old. So... I had the brilliant idea that I would change it. I got a squeeze bulb and sucked out all the old fluid and replaced it with new P.S. fluid... supposedly the correct (Prestone) fluid for Ford vehicles.

Not long afterward, I noticed a puddle growing under the left front tire. You guessed it... power steering fluid. Haven't figured out exactly where it's coming from yet... the pump itself or a seal, valve, hose, fitting somewhere else etc. I'm guessing one of these old parts didn't like the new type fluid.

Has this happened to any of y'all? Anyone have any ideas/suggestions as to what went wrong? Is the whole system ruined? Any help would be appreciated.
Wish I'd have just left the old muddy crap in there.