Thermostat Bypass Pipes Replacement 6.6L Engine

1. Remove the thermostat housing. Refer to Thermostat Housing Crossover Replacement .
2. Remove the thermostat bypass pipe and O-ring seal from the thermostat housing.
3. Remove and discard the O-ring seal.
4. Clean the sealing surfaces of the bypass pipe.
5. Clean the water pump and the thermostat housing crossover sealing surfaces.

1. Install a new O-ring seal on the thermostat bypass pipe.
2. Lightly lubricate the O-ring seal with coolant.
3. Install a new O-ring seal for the bypass pipe to the water pump.
4. Install the bypass pipe in the thermostat housing.
5. Install the thermostat housing. Refer to Thermostat Housing Crossover Replacement .