Originally Posted by pastorbobnlnh

I just checked the pressure after a 20 hour wait. It dropped from 100psi to just below 20psi. So not the valve core.

I'll try to find time today to pull the wheel off, dunk in water to see if a leak is detectable and will add sealant. The current condition of the tread and sidewall doesn't merit a full-blown repair. This tire has given me nine years of use with no issues until now. Tubular life is good!