Q: How Can You Check the Operation of a Water Pump?
A: A failure in the water pump can cause serious engine damage due to overheating. There are three 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. In most cases, you'll need a flashlight to find the hole on the water pump from underneath to check for leaks. Some small black staining around the weep hole is normal. If the stain is heavy brown or actual coolant is evident, replace the pump. If the water pump shaft bearings fail, there may be a howling sound at the front of the engine while it's running. With the engine off, shaft wear can be felt if the water pump pulley is rocked up-and-down. Don't mistake drivebelt slippage, which causes a squealing sound, for water pump bearing failure. A quick water pump performance check is to put the heater on. If the pump is failing, it won't be able to efficiently circulate hot water all the way to the Heater Core as it should.
A: Disconnect the cable from the negative battery terminal. Drain the cooling system. Remove the accessory drivebelts. Remove the timing belt cover, timing belt, timing belt tensioner, and rear timing belt cover. Remove the bolts attaching the water pump to the engine block and remove the pump from the engine. Clean the bolt threads and threaded holes in the engine to remove corrosion and sealant. Compare the new pump to the old one to ensure they are identical. Install a new O-ring seal in the groove that lines the water pump body and apply a thin film of RTV sealant to hold the seal in place during installation. Carefully mate the pump to the engine. Install the water pump bolts and tighten them to the specified torque. The remainder of the installation is the reverse of removal. Refill the cooling system and check for leaks after running the engine.