Hi Guys, when I read Ian's comment:

 "Instal a car tubeless valve
for pressure testing."

Ian RV6A Australia.

I remembered finding a Schrader valve (tubeless tire valve) with male 1/8"
NPT threads on one side.  I bought one thinking this would be a neat way to
check pressure and perhaps bleed the cooling system of bubbles.
Just passing along a small idea.

Regards, Tommy James<><