The bearings are separated from the coolant by a seal. Once that seal leaks, coolant will get to the bearings and pour out the holes. Usually the seal doesn't fail until the bearings are heavily worn.
If the seal was nicked during assembly by a guy (who gets paid a cup of rice a day) because he was working too fast to avoid the caning, a premature seal failure would result.
Maybe the next "new" one will be fine.
At least a water pump is easy to get to and easy to replace.
Carl
