Leaky brake pressure reg. in 4kq stopped leaking!

[Luis Felipe Patiño]

I did not do anything, except to keep topping the fluid off, and to pump the
brakes during normal braking. I didn't even try sealing it with black
silicone (thanks, Ben) or replace it with new bpr (thanks Chris).

Now, for two weeks the fluid level has remained stable, and does  not even
drip, whereas before it left  _puddles_ requiring addition of ~500 mL/week.
Curiously, the 4kq now brakes rock-solid (though it never braked poorly).

Was (is) the bpr really the problem, or was (is) something else wrong with
my brake system?