Water Pump Replacement 4.8L, 5.3L, and 6.0L Engines
Removal Procedure
- Drain the cooling system. Refer to
Cooling System Draining and Filling
.
- Loosen the air cleaner outlet duct clamps at the following locations:
• | Mass airflow/intake air temperature (MAF/IAT) sensor |
- Remove the radiator inlet hose clip from the outlet duct.
- Remove the air cleaner outlet duct.
- If necessary, remove the engine sight shield.
Refer to
Upper Intake Manifold Sight Shield Replacement
in
Engine Mechanical - 4.8L, 5.3L, and 6.0L.
- Remove the radiator vent inlet hose from the radiator hose clips.
- Reposition the inlet hose clamp at the
water pump.
- Remove the inlet hose from the water pump.
- Remove the fan blade. Refer to
Fan Replacement
.
- Remove the accessory drive belt. Refer to
Drive Belt Replacement - Accessory
in Engine Mechanical - 4.8L, 5.3L,
and 6.0L.
- Reposition the outlet hose clamp at the
water pump.
- Remove the outlet hose from the water pump.
- Reposition the surge tank outlet hose clamp
at the water pump.
- Remove the surge tank outlet hose from the water pump.
- Reposition the heater inlet hose clamp
at the water pump.
- Remove the heater inlet hose from the water pump.
- Remove the water pump bolts.
- Remove the water pump and gaskets.
- Discard the water pump gaskets.
Installation Procedure
Important: All gaskets surfaces are to be free of oil or other foreign material during
assembly.
- Install the water pump and NEW gaskets.
Notice: Use the correct fastener in the correct location. Replacement fasteners
must be the correct part number for that application. Fasteners requiring
replacement or fasteners requiring the use of thread locking compound or sealant
are identified in the service procedure. Do not use paints, lubricants, or
corrosion inhibitors on fasteners or fastener joint surfaces unless specified.
These coatings affect fastener torque and joint clamping force and may damage
the fastener. Use the correct tightening sequence and specifications when
installing fasteners in order to avoid damage to parts and systems.
- Install the water pump bolts.
Tighten
- Tighten the bolts a first pass to 15 N·m (11 lb ft).
- Tighten the bolts a final pass to 30 N·m (22 lb ft).
- Install the heater inlet hose to the water
pump.
- Position the heater inlet hose clamp at the water pump.
- Install the surge tank outlet hose to the
water pump.
- Position the surge tank outlet hose clamp at the water pump.
- Install the outlet hose to the water pump.
- Position the outlet hose clamp at the water pump.
- Install the accessory drive belt. Refer to
Drive Belt Replacement - Accessory
in Engine Mechanical - 4.8L, 5.3L,
and 6.0L.
- Install the fan blade. Refer to
Fan Replacement
.
- Install the inlet hose to the water pump.
- Position the inlet hose clamp at the water pump.
- Install the engine vent inlet hose to the
radiator hose clips.
- If necessary, install the engine sight shield. Refer to
Upper Intake Manifold Sight Shield Replacement
in Engine Mechanical - 4.8L, 5.3L, and
6.0 L.
Important: Align the arrow at the throttle body end of the duct with the throttle body
attaching stud.
- Install the air cleaner outlet duct.
- Install the radiator inlet hose clip to the outlet duct.
- Tighten the air cleaner outlet duct clamps at the following locations:
Tighten
Tighten the clamps to 7 N·m (62 lb in).
- Fill the cooling system. Refer to
Cooling System Draining and Filling
.
Water Pump Replacement 4.3L Engine
Tools Required
J 41240 Fan Clutch Remover
and Installer
Removal Procedure
- Loosen the air cleaner outlet duct clamp
at the mass airflow/intake air temperature sensor.
- Remove the positive crankcase ventilation
(PCV) hose.
- Remove the air cleaner adapter nut.
- In order to remove the air cleaner outlet
duct, pivot the duct upward until the hinge clip release from the lip on the throttle
body.
- Drain the cooling system. Refer to
Cooling System Draining and Filling
.
- Remove the cooling fan. Refer to
Fan Replacement
.
- Remove the drive belt. Refer to
Drive Belt Replacement
in Engine Mechanical - 4.3L.
- Reposition
the radiator outlet hose clamps at the surge tank and water pump.
- Remove the radiator outlet hose from the surge tank.
- Remove the radiator outlet hose from the water pump.
- Reposition the water pump inlet hose clamps.
- Remove the water pump inlet hose.
- Using J 41240
, hold the water pump pulley, remove the water pump pulley bolts.
- Remove the water pump bolts.
- Remove the water pump.
- Remove and discard the water pump gaskets.
- Clean and inspect the water pump, if necessary. Refer to
Water Pump Cleaning and Inspection
.
Installation Procedure
- If reusing the old fasteners, apply sealant GM P/N 12346004, (Canadian P/N 10953480),
or equivalent to the threads of the water pump bolts.
- Install NEW water pump gaskets and the water pump.
Notice: Use the correct fastener in the correct location. Replacement fasteners
must be the correct part number for that application. Fasteners requiring
replacement or fasteners requiring the use of thread locking compound or sealant
are identified in the service procedure. Do not use paints, lubricants, or
corrosion inhibitors on fasteners or fastener joint surfaces unless specified.
These coatings affect fastener torque and joint clamping force and may damage
the fastener. Use the correct tightening sequence and specifications when
installing fasteners in order to avoid damage to parts and systems.
- Install the water pump bolts.
Tighten
Tighten the bolts to 45 N·m (33 lb ft).
- Using J 41240
, hold the water pump pulley, install the water pump pulley bolts.
Tighten
Tighten the bolts to 25 N·m (18 lb ft).
Important: After assembly, the hose clamp tangs (water
pump end) must point forward and the upper tang should be level with the outside
diameter of the water pump inlet hose.
- Install the water pump inlet hose.
- Position the water pump inlet hose clamps.
- Install
the radiator outlet hose to the water pump.
- Install the radiator outlet hose to the surge tank.
- Position the radiator outlet hose clamps at the surge tank and water
pump.
- Install the drive belt. Refer to
Drive Belt Replacement
in Engine Mechanical -4.3L.
- Install the cooling fan. Refer to
Fan Clutch Replacement
.
- Align the hinge clip with the lip on the
throttle body.
In order to install the air cleaner outlet duct, pivot
the air cleaner outlet duct downward until the mounting stud is through the hole.
- Install the air cleaner adapter nut.
- Install the PCV hose.
- Tighten the air cleaner outlet duct clamp
at the MAF/IAT sensor.
Tighten
Tighten the clamps to 4 N·m (35 lb in).
- Fill the cooling system. Refer to
Cooling System Draining and Filling
.
- Inspect the cooling system for leaks.
Water Pump Replacement 8.1L
Removal Procedure
- Drain the cooling system. Refer to
Cooling System Draining and Filling
.
- Remove the drive belt. Refer to
Drive Belt Replacement - Accessory
.
- Remove the fan clutch. Refer to
Fan Clutch Replacement
.
- Reposition the outlet hose clamp at the water pump.
- Remove the outlet hose from the water pump.
- Reposition the bypass hose clamps at the water pump and water crossover.
- Remove the bypass hose.
- Remove the water pump bolts.
- Remove the water pump.
- Remove and discard the water pump gaskets.
Installation Procedure
- Place NEW water pump gaskets into place.
- Install the water pump.
Notice: Use the correct fastener in the correct location. Replacement fasteners
must be the correct part number for that application. Fasteners requiring
replacement or fasteners requiring the use of thread locking compound or sealant
are identified in the service procedure. Do not use paints, lubricants, or
corrosion inhibitors on fasteners or fastener joint surfaces unless specified.
These coatings affect fastener torque and joint clamping force and may damage
the fastener. Use the correct tightening sequence and specifications when
installing fasteners in order to avoid damage to parts and systems.
- Install the water pump bolts.
Tighten
Tighten the bolts to 50 N·m (37 lb ft).
- Install the bypass hose.
- Position the bypass hose clamps at the water pump and water crossover.
- Install the outlet hose to the water pump.
- Position the outlet hose clamp at the water pump.
- Install the fan clutch. Refer to
Fan Clutch Replacement
.
- Install the drive belt. Refer to
Drive Belt Replacement - Accessory
.
- Fill the cooling system. Refer to
Cooling System Draining and Filling
.
Water Pump Replacement 6.6L (LB7) Engine
Removal Procedure
- Remove the left fender wheelhouse inner panel. Refer to
Wheelhouse Panel Replacement
in Body Front End.
- Drain the engine coolant and the engine block. Refer to
Cooling System Draining and Filling
.
- Remove the thermostat housing crossover. Refer to
Thermostat Housing Crossover Replacement
.
- Remove the fan clutch. Refer to
Fan Clutch Replacement
.
- Remove the crankshaft balancer. Refer to
Crankshaft Balancer Replacement
in Engine Mechanical - 6.6L.
- Remove the oil cooler inlet pipe to water pump nuts.
- Remove the engine wiring harness retainer from the inner stud.
- Remove the water pump bolts. Note the location of the bolts. The bolts are three different lengths.
- Remove the water pump.
- Remove the water pump outlet pipe gasket.
- If required, clean and inspect the water pump. Refer to
Water Pump Cleaning and Inspection
in Engine Mechanical - 6.6L.
Installation Procedure
- Lubricate the water pump O-ring with engine oil.
- Install the water pump.
Notice: Refer to Fastener Notice in the Preface section.
- Install the water pump bolts. Ensure the correct length bolt is used in the proper location.
Tighten
Tighten the bolts to 21 N·m (15 lb ft).
- Install the water pump to oil cooler inlet pipe gasket.
- Install the engine wiring harness retainer on the water pump outlet pipe inner stud.
- Install the water pump to oil cooler inlet pipe nuts.
Tighten
Tighten the nuts to 21 N·m (15 lb ft).
- Install the thermostat housing crossover. Refer to
Thermostat Housing Crossover Replacement
.
- Install the crankshaft balancer. Refer to
Crankshaft Balancer Replacement
in Engine Mechanical - 6.6L.
- Install the fan clutch. Refer to
Fan Clutch Replacement
.
- Fill the engine with coolant. Refer to
Cooling System Draining and Filling
.
- Install the left fender wheelhouse inner panel. Refer to
Wheelhouse Panel Replacement
in Body Front End.
Water Pump Replacement 6.6L (LLY)
Removal Procedure
- Remove the left wheelhouse inner panel. Refer to
Wheelhouse Panel Replacement
in Body Front End.
- Remove the thermostat housing crossover. Refer to
Thermostat Housing Crossover Replacement
.
- Remove the crankshaft balancer. Refer to
Crankshaft Balancer Replacement
in Engine Mechanical - 6.6L (LLY).
- Remove the water pump to engine coolant pipe nuts.
- Remove the engine wiring harness retainer from the inner stud.
- Remove the water pump bolts. Note the location of the bolts. The bolts are three different lengths.
- Remove the water pump.
- Remove and discard the water pump O-ring and coolant pipe gasket.
- If required, clean and inspect the water pump. Refer to
Water Pump Cleaning and Inspection
in Engine Mechanical - 6.6L (LLY).
Installation Procedure
- Lubricate the water pump O-ring with engine oil.
- Install the engine coolant pipe gasket and water pump O-ring.
Notice: Refer to Fastener Notice in the Preface section.
- Install the water pump.
- Install the water pump bolts. Ensure the correct length bolt is used in the proper location.
Tighten
Tighten the bolts to 21 N·m (15 lb ft).
- Install the engine wiring harness retainer on the water pump outlet pipe inner stud.
- Install the water pump to engine coolant pipe nuts.
Tighten
Tighten the nuts to 21 N·m (15 lb ft).
- Install the thermostat housing crossover. Refer to
Thermostat Housing Crossover Replacement
.
- Install the crankshaft balancer. Refer to
Crankshaft Balancer Replacement
in Engine Mechanical - 6.6L (LLY).
- Install the left wheelhouse inner panel. Refer to
Wheelhouse Panel Replacement
in Body Front End.