GM 12637105
Water Pump

Starting engine repair requires draining the cooling system of 4.8l, 5.3l, and 6.0l engines. Unfasten the air inlet duct connectors at Throttle Body and maf/iat sensor before detaching the radiator inlet hose from outlet duct. You can take off the engine sight shield and the radiator vent inlet hose after unclipping them from their radiator hose connection points. Adjust the inlet hose clamp from its position on the Water Pump before taking out the hose. Also detach the Fan Blade when needed. Then take off the outlet hose from the Water Pump after moving the outlet hose clamp. Position the surge tank outlet hose clamp differently and remove the surge tank outlet hose before doing the same with the heater inlet hose. To access the Water Pump compartment you must remove bolts then bring out this component along with its gaskets before discarding the gaskets. Before setting the Water Pump in place apply new gaskets only when you confirm all surface areas remain without oil or contamination. Handtighten the Water Pump bolts to 15 nm before tightening to their final torque of 30 nm. Secure the heater inlet hose with its clamp then the surge tank outlet hose together with its clamp. Finally put back on the outlet hose and its clamp. Reassemble the accessory Drive Belt and Fan Blade according to need while attaching both ends of the inlet hose with its clamp. Reposition the engine vent inlet hose to its original position on the radiator hose clamps and the engine sight shield when you reinstall it. Position the arrow on the end of the Throttle Body duct to match the Throttle Body screw and connect the air cleaner outlet duct. Place the radiator inlet hose clip on top of the outlet duct before securing the Throttle Body and maf/iat sensor air cleaner outlet duct clamps at 4 nm (35 inch lbs.). Afterwards, fill the cooling system.

Before changing the auxiliary water pump, drain the cooling system. Remove old 2 bolts and can (non-screw clamp bolts on inlet hose) from the front heater inlet hose . Next, connect the rear heater inlet hose clamp and disconnect the rear heater inlet hose, then reposition the rear heater inlet hose clamp . Unclip the heater outlet hose and remove electrical connection from the auxiliary water pump. Take out the nuts from the auxiliary water pump bracket and remove the auxiliary water pump from the vehicle. Remove the clips from the auxiliary water pump bracket then also the auxiliary water pump from the bracket. For installation, the auxiliary water Pump should be installed to the auxiliary water pump Bracket and clips should then be attached to the bracket. On the next step, install the auxiliary water pump back in the vehicle, with nuts to the auxiliary water pump bracket being secured to the nuts of 9 Nm (80 inch lbs.). The auxiliary water pump is connected to the electrical connector, install the heater outlet hose into the clip, and the rear heater inlet hose is installed into the auxiliary water pump. Set the rear heater inlet hose clamp and attach front heater inlet hose to auxiliary water pump and set the front heater inlet hose clamp. Finally, fill the cooling system.

Ensure all gasket surfaces are free of oil or foreign material.

Remove the water pump bolts and take out the water pump along with the gaskets, discarding the old gaskets.

Install the accessory drive belt, position the radiator inlet hose and vent inlet hose correctly, and secure the radiator inlet hose with the clamp.

Place new water pump gaskets.