GM Service Manual Online
For 1990-2009 cars only
Makes
🢒
GMC_Truck
🢒
2008
🢒
TopKick C-Series (Conventional) C4/C5
🢒
Engine
🢒
Engine Cooling
🢒 Thermostat Bypass Pipes Replacement
Thermostat Bypass Pipes Replacement 6.6L LLY
Removal Procedure
Remove the drive belt. Refer to
Drive Belt Replacement
for the 6.6L (LLY) engine.
Remove the bypass pipe from the thermostat housing
Remove and discard the O-ring seals from the bypass pipe and the water pump.
Clean the sealing surfaces of the bypass pipe.
If required, clean and inspect the bypass pipe and thermostat housing. Refer to
Engine Coolant Thermostat Housing Cleaning and Inspection
for the 6.6L (LLY) engine.
Installation Procedure
Install a NEW O-ring seal onto the bypass pipe.
Install a NEW O-ring seal to the water pump.
Lubricate the O-ring seals with clean engine coolant.
Install the bypass pipe into the thermostat housing.
Install the drive belt. Refer to
Drive Belt Replacement
for the 6.6L (LLY) engine.
Thermostat Bypass Pipes Replacement 6.6L LMM
Removal Procedure
Remove the thermostat housing. Refer to
Thermostat Housing Crossover Replacement
.
Remove the bypass pipe from the thermostat housing.
Remove and discard the O-ring seals from the bypass pipe and the water pump.
Clean the sealing surfaces of the bypass pipe.
If required, clean and inspect the bypass pipe and thermostat housing. Refer to
Engine Coolant Thermostat Housing Cleaning and Inspection
.
Installation Procedure
Install a NEW O-ring seal onto the bypass pipe.
Install a NEW O-ring seal to the water pump.
Lubricate the O-ring seals with clean engine coolant.
Install the bypass pipe into the thermostat housing.
Install the thermostat housing. Refer to
Thermostat Housing Crossover Replacement
.