[s-cars] Expansion tank replace or just a hose clamp?

[Toborg Michael (AC-SM/ESC3) *]

I seem to be adding coolant to my 95 S6 a little too often recently.
I've noticed evidence of the expansion tank leaking or boiling over once
in a while. If I twist by hand the small hose that goes from the top of
the expansion tank to the upper radiator hose, I can hear pressure
leaking out when the car is hot, so I guess this is the source of the
leak.
It has a crimp-on style clamp, that I plan to replace with a screw type
hose clamp. Is this a common failure point? I notice that parts direct
from s-cars.org sells new expansion tanks. Are these plastic tanks know
to leak or crack?
The temp gauge has never said anything more than normal temps, so I
don't think the car is getting too hot, but I have been in a lot of
traffic recently.
Any BTDT? 

Thanks, Mike