GM 12657499 Engine Coolant Pump Kit

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To remove the water pump, start by disconnecting the cable from the negative battery terminal and draining the cooling system. Remove the drivebelt, right-side engine strut mount, and mount bracket. Hold the water pump pulley with a strap wrench or pin spanner and remove the pulley mounting bolts and pulley. Then, remove the water pump mounting bolts and carefully remove the pump from the engine. Clean the mating surface of the engine and the water pump if it will be reinstalled. To install the new water pump, compare it with the old one to ensure they are identical. Place the gasket and water pump into position and install the new mounting bolts. Tighten the water pump mounting bolts in a criss-cross pattern to the specified torque. Finally, tighten the water pump pulley bolts, refill the cooling system with the proper antifreeze concentration, and start the engine to check for leaks while it reaches normal operating temperature.

Disconnect all hoses from the water pump and secure them out of the way.

Disconnect the cable from the negative battery terminal. Raise the vehicle and support it securely on jackstands. Remove the under-vehicle splash shield. Drain the cooling system. If the coolant is relatively new and in good condition, save it and reuse it. Once the coolant has drained, lower the vehicle. Remove the drivebelt. Remove the air filter housing and air intake duct/resonator. For V6 engines, use a pin spanner or strap wrench to hold the water pump pulley from turning, and remove the pulley mounting bolts and pulley. Remove the bolts attaching the water pump to the timing chain cover and remove the pump from the engine. If the water pump is stuck, gently tap it with a soft-faced hammer to break the seal. Clean the bolt threads and the threaded holes in the engine and remove all corrosion and sealant. Remove all traces of old gasket material from the sealing surfaces. For V8 engines, remove the engine cover. On non-supercharged models, remove the drivebelt tensioner and the idler pulley mounting bolt and pulley. On supercharged models, remove the supercharger drivebelt and tensioner, then remove the tensioner bracket bolts and bracket. Disconnect and remove the hoses to the water pump. Unbolt and remove the water pump from the front of the engine. It may be necessary to tap the pump with a soft-face hammer to break the gasket seal. To install, remove the gaskets from the engine, then compare the new pump and replacement gaskets to the old ones to make sure that they're identical. Apply a thin film of RTV sealant to hold the new gasket in place during installation. O-rings should be coated with clean coolant. Make sure the gasket is correctly positioned on the water pump and the mating surfaces are clean and free of old gasket material. Carefully mate the pump to the water pump housing. On V6 models, install the bolts and, following the recommended sequence, tighten the bolts to the torque. On V8 models, install the water pump bolts and tighten them, a little at a time, to the torque. The remainder of installation is the reverse of removal. Refill the cooling system. Operate the engine to check for leaks.

To replace the water pump in a vehicle, start by disconnecting the cable from the negative battery terminal and draining the cooling system, saving the coolant if it's in good condition. For 3.0L, 3.4L, and 3.6L engines, loosen the water pump pulley bolts without removing them, then remove the drivebelt and the pulley. On 2.4L engines, remove the air filter housing, intake manifold, exhaust manifold heat shield, and coolant heater if equipped. Loosen the lug nuts on the right front wheel, raise the vehicle, and remove the wheel and inner fender splash shield. Remove the catalytic converter and the thermostat housing and water pipe, separating them and discarding the O-ring seals. Remove the cover over the water pump sprocket and drain excess coolant from the pump. Install a special holding tool onto the water pump sprocket and remove all water pump-to-sprocket bolts. Remove the bolts attaching the water pump to the engine block and remove the pump. Clean the bolt threads, threaded holes, and sealing surfaces. Install a new sealing ring into the pump and use a threaded stud as a guide pin to align the water pump sprocket with the flange during installation. Tighten the water pump mounting bolts and sprocket bolts to the proper torque specifications. Install the water pump access cover, thermostat housing, and water pipe, and refill the cooling system with the correct antifreeze concentration. Start the engine and check for leaks.

Yes, even if a water pump shows no outward signs of a problem such as noise or leakage, it may still need to be replaced.

1. Compare the new water pump with the old one to ensure they are identical. 2. Place the gasket and water pump into position. 3. Install the new mounting bolts. 4. Tighten the water pump mounting bolts in a criss-cross pattern to the specified torque.

A failure in the water pump can cause serious engine damage due to overheating. If a failure occurs in the shaft seal, coolant will leak from the engine front cover or a hole that is exposed externally near the shaft seal. Water pumps are equipped with weep or vent holes. It is possible to check the water pump weep hole using a flashlight. If a failure occurs in the shaft seal, coolant will leak from the hole. Use the flashlight to find the hole(s) on the water pump and check for leaks. The hole(s) can be found on the top or bottom of the pump body usually near the shaft seal. If the water pump shaft bearings fail, there may be a howling sound near the water pump 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 turn the heater on. If the pump is failing, it might not be able to efficiently circulate hot water all the way to the heater core as it should.

First, remove the drive belt and drain the cooling system, taking care to clean up any spilled coolant. On four-cylinder engines, locate the additional drain plug on the water pump's bottom. For four-cylinder engines, disconnect the ECT sensor's electrical connector and remove it, also removing any harnesses attached to the thermostat housing. Disconnect the outlet hose on the expansion tank and the radiator hose from the thermostat housing cover. Remove the exhaust manifold heat shield. Disconnect the heater hoses from the thermostat housing and remove the housing mounting bolts, then separate the water pipe from the thermostat housing and replace the old O-ring seals with new ones. Loosen the right front wheel lug nuts, raise the vehicle, and remove the wheel and fender splash shield. Remove the cover over the water pump sprocket, install a special holding tool onto the water pump sprocket or use a homemade tool to lock the sprocket in place, remove all water pump-to-sprocket bolts, and then remove the water pump from the engine. Clean bolt threads, threaded holes, and sealing surfaces, and remove any old gasket material and the sealing ring from the water pump. Install a new sealing ring and the water pump, aligning it with the water pump sprocket. Tighten the water pump mounting bolts and sprocket bolts, then install the water pump access cover and thermostat housing and water pipe, lubricating the seal lightly with silicone gel. The remaining steps involve the reverse of removal, including reinstalling the drive belt, tightening pulley bolts, and refilling the cooling system with the proper antifreeze concentration. For V6 engines, remove the air duct, loosen water pump pulley bolts, and remove the drive belt. Remove the pulley and water pump mounting bolts, clean the mounting bolt threads and engine threaded holes, compare the replacement pump, clean mating surfaces with lacquer thinner or acetone, apply RTV sealant to the new gasket, and install the gasket and water pump. Tighten the water pump mounting bolts and pulley bolts, and then complete the installation by refilling the cooling system and checking for leaks as the engine reaches normal operating temperature.

A failure in the water pump can lead to serious engine damage as it causes overheating. These models have a water pump that is driven by the drivebelt. Water pumps are typically equipped with weep or vent holes, which can leak coolant if there is a failure in the pump seal. To check for leaks, a flashlight and small mirror can be used to locate the hole on the water pump. If the water pump shaft bearings fail, there may be a howling sound while the pump is running, and shaft wear can be felt by rocking the water pump pulley up and down with the drivebelt removed. It is important not to mistake drivebelt slippage, which causes a squealing sound, for water pump bearing failure. Even if a pump shows no outward signs of a problem, such as noise or leakage, it may still need to be replaced. The only sure way to determine this is through removal for close examination. A quick check of water pump performance is to turn on the heater. If the pump is failing, it may not be able to efficiently circulate hot water to the heater core as it should.