After investigation, It was found that abnormal in bearing is unsmooth rotation by running test. It is possible causes that the Bearing damage, after cutting and disassemble part for investigation found that seal ring was wear and found rust around CASE. It is possible causes that the Temperature of seal contact surface was high because of, user was not used LLC. Then, after the seal ring wear, it made the Liquid intrusion, grease degradation.
Therefore this might be the main possible cause of Water Pump damage.