It could be. The seal on that end is an o-ring on the housing head. It's possible that the movement of the head has eventually deteriorated the o-ring to the point that it's leaking. Here is an excellent video going through a power steering chuck.
Power Steering Chuck Training VideoThis is of course assuming that this is the style of power steering chuck you have.
Thanks, I found that video, and then another similar one that was a little newer (like 1974 or so).
That's a good point on why it came loose, I am not really sure. Maybe just 50 years of not having any attention paid to it...
Got to decide what I want to do: try to fix this one myself (which would basically consist of just trying to get it to not leak), go to a Borgeson or Firm Feel box, or maybe put a manual box on it.