Mark wrote:
does this model of tank have a bladder to seperate the air and the
water?

Yes, it does. Does this provide additional info that can help?

BTW, I followed marks542's suggestion: I put a bicycle air pump with
pressure gage (an auto tire one won't work because the threaded valve
on the tank fits a bicycle pump, not an auto tire one) and attempted to
measure.

My first observation was that **no water is leaking** (that's good,
right?)

However, the pressure gauge on my bicycle pump only starts to show
calibrated reading from 20 psi and above. The Extrol 30 needs only
12psi. I heard some air discharging in the process and so I was afraid
to depleat the air in the tank (which would exacerbate the problem -
not good on a Sunday morning...).

BTW, the air that came out of that valve was stinky (like dead fish or
something). Weird.

What do you suggest that I do next?

Thank you all for your help!
Sam