The leak is caused by a worn out bearing. Once the shaft starts wobbling, the seal can no longer do its job. Try to avoid over-tightening the fan belt, as this can significantly shorten the life expectancy of water pump bearing, as well as those in the generator/alternator.
Carl

1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission