Honda 19200-P8A-A02 Water Pump (Yamada)

A failure in the water pump can cause serious engine damage due to overheating. There are two ways to check the operation of the water pump while it's installed on the engine. If the pump is defective, it should be replaced with a new or rebuilt unit. Water pumps are equipped with weep (or vent) holes. If a failure occurs in the pump seal, coolant will leak from the hole. With the timing belt cover removed, a flashlight and small mirror are needed to find the hole on the water pump from underneath to check for leaks. If the water pump shaft bearings fail, there may be a howling sound at the pump while it's running. Shaft wear can be felt with the timing belt removed if the water pump pulley is rocked up and down with the engine off. Drivebelt slippage, which causes a squealing sound, should not be mistaken for water pump bearing failure. Even a pump that exhibits no outward signs of a problem, such as noise or leakage, can still be due for replacement. Removal for close examination is the only sure way to tell. Sometimes the fins on the back of the impeller can corrode to the point that cooling efficiency is hampered.