Toyota 16100-39455 Engine Water Pump Assembly

Non-toxic coolant is available at local auto parts stores. Although the coolant is non-toxic when fresh, proper disposal of used coolant is still required. For a four-cylinder engine, start by disconnecting the negative battery cable and draining the cooling system. Then, remove the engine movement control rod and its bracket, as well as the #2 engine stay and bracket. Take off the drivebelt and the alternator, followed by the water pump pulley. Remove the four bolts and two nuts to pry the water pump off, tapping it loose if necessary. Clean the water pump and block, apply a new bead of sealant, and install the water pump. Finally, refill the cooling system, run the engine, and check for leaks and proper operation. For a V6 engine, begin by disconnecting the negative battery cable and draining the cooling system. Remove the timing belt and camshaft sprockets, then take off the water inlet pipe and thermostat. Remove the number 3 timing belt cover and the water pump retaining bolts/nuts to separate the pump from the engine. Thoroughly clean all sealing surfaces and install a new metal/rubber gasket. Reinstall the pump and the remaining parts, tightening the water pump bolts/nuts in several steps. Refill the cooling system and run the engine, checking for leaks and proper operation.

Engine damage can occur from a faulty water pump due to overheating. To check the pump, squeeze the upper radiator hose with the engine running at normal temperature. A pressure surge should be felt if the pump is working. Water pumps have weep holes, which leak coolant if the pump seal fails. Use a flashlight to find the hole, located behind the pulley below the pump shaft. Gray discoloration around the hole is normal, but dark brown stains indicate a problem. A howling sound may indicate failing pump shaft bearings, which can also be detected by rocking the pump pulley. Don't confuse drive belt slippage, causing a squealing sound, with pump failure. Use belt dressing to rule out belt noise.

Disconnect the cable from the negative battery terminal and drain the cooling system.

Disconnect the cable from the negative battery terminal and drain the cooling system.

Bearing wear can be felt if the water pump pulley is rocked up and down.