As investigation result, this water pump was found trace of leakage in drain hole and. For impeller water pump was found rusty which might occurred by LLC was not applied. Result of leakage test was leak. Water pump leakage is possible that caused by the LLC was not applied and might there is contamination in Cooling system resulted in seal leak, Bearing damage is possible that water or LLC leak off cooling system, then leak in Bearing resulted in bearing damage, bearing operated centrifugal force of bearing shaft’s imbalance and occurred load on seal surface resulted in Seal crack and LLC leak off system.