You will need a fan clutch removal tool (J41240) to work on the 4.3l engine Water Pump replacement project. Detach the air cleaner outlet duct clamp near the mass airflow sensor then disconnect the pcv hose and air cleaner adapter nut. Push the air cleaner outlet duct upwards to pop out its clasp from the
Throttle Body edge. Open the cooling system drains then remove the cooling fan and belt. Move radiator outlet hose clamps from surge tank to Water Pump location and take off hose from both devices. Realign the Water Pump inlet clamp fasteners before you pull out the inlet hose assembly. Using the j41240 fan clutch tool, grasp the Water Pump Pulley and unscrew its bolts before removing all Water Pump screws to extract the Water Pump. Remove and throw away the old Water Pump gaskets before cleaning and inspecting the Water Pump. During bolt reuse apply gm p/n 12346004 sealant (Canadian P/N 10953480) to Water Pump bolt threads. Place new Water Pump gaskets properly on the pump surface and attach the Water Pump while using the right fasteners at their designated positions. Secure the Water Pump Pulley with the fan clutch remover and installer j41240 tool. Next, fasten and tighten the Water Pump bolts to 33 ft. Lbs. (45 Nm). Bring forward the hose clamp tangs on the Water Pump side and position the top clamp at the same level as the Water Pump inlet hose outer edge before installing both pieces. Attach the radiator outlet hose to its connections on the Water Pump and surge tank while setting the clamps correctly. Turn the cooling fan in place with the
Drive Belt installed before sinking the mounting stud through the Throttle Body opening and lowering the air cleaner outlet duct into position. Secure the pcv hose and air cleaner adapter nut. Also tighten the maf/iat sensor air cleaner outlet duct clamp to 35 inch lbs. To finish the assembly process you should top off the cooling system and look for fluid leaks.