Gasket was OK but o-ring brand or manufacture failed! Big time. ASE Master Tech x 30+ years has probably replaced about 100 sets of timing belts on these Toyota engines. Fill the o-ring groove with synthetic grease, carefully insert the o-ring and gently squeeze your fingers around it and along with the pump. Never had a single leak. This o-ring looked like a ring, but it "packed" and didn't fit in its groove. Heated, rolled up, even stretched a little, all to no avail. Just as he was about to…