"I have done the typical intensive sanding, fluxing and re-soldering
several
times with no success. Any other suggestions as to how to stop this
leak without having to
soldering another "T" and corresponding connectors into its place.
Thanks. "

What exactly do you have? Normally a soldered tee is all there is to
it and there are no "corresponding connectors." If it's just a regular
T, I would not have tried resoldering it several times. I would have
just replaced it.