Thermostat Housing Crossover Replacement

Thermostat Housing Crossover Replacement (LMM)

Removal Procedure




1. Remove the air cleaner.
2. Drain the cooling system. Refer to Cooling System Draining and Filling (Static Fill) Cooling System Draining and Filling (Vac-N-Fill).
3. Disconnect the negative battery cables. Refer to Battery Negative Cable Disconnection and Connection (w/Single Battery) Battery Negative Cable Disconnection and Connection (w/Auxiliary Battery) Battery Negative Cable Disconnection and Connection (w/Dual Batteries).
4. Remove the drive belt.
5. Disconnect the air conditioning (A/C) pressure switch electrical connector (1).
6. Disconnect the A/C compressor clutch electrical connector (2).
7. Remove the generator bracket.
8. Remove the front oil fill tube.




9. Disconnect the engine coolant temperature (ECT) sensor electrical connectors.
10. Remove the water outlet.
11. Without disconnecting the power steering hoses, remove the power steering pump bolts and the power steering pump. Reposition the power steering pump and secure to the side. Refer to Power Steering Pump Replacement (4.8L, 5.3L, 6.0L, and 6.2L) Power Steering Pump Replacement (6.6L) Power Steering Pump Replacement (4.3L).
12. Remove the power steering pump bracket.




13. Remove the bolts and wiring harness bracket at the thermostat housing.
14. Position the bracket and wiring harness aside.
15. Remove the cooling fan pulley.




16. Reposition the turbocharger coolant return pipe hose clamp.
17. Remove the turbocharger coolant return pipe hose.




18. Remove the fuel line bracket bolt at the thermostat housing crossover.




19. Remove the water pump inlet pipe bolts.




20. Remove the thermostat housing crossover bolts and nuts.
21. Remove the thermostat housing crossover, with the bypass pipe.
22. Remove and discard the thermostat bypass pipe to water pump O-ring seal.
23. Remove and discard the thermostat housing crossover gaskets.
24. If necessary, perform the following:

1. Remove the thermostat bypass pipe from the thermostat housing crossover.
2. Remove and discard the thermostat bypass pipe O-ring seal.
3. Remove the thermostat cover bolts and cover.
4. Remove the thermostats.
5. Remove and discard the thermostat seals.

25. If required, clean and inspect the thermostat housing. Refer to Engine Coolant Thermostat Housing Cleaning and Inspection.

Installation Procedure





Notice: Refer to Fastener Notice.

1. If necessary, perform the following:

1. Install NEW seals to the thermostats.
2. Install the thermostats.
3. Install the thermostat cover and bolts.

Tighten the bolts to 21 N.m (15 lb ft).

4. Install a NEW O-ring seal to the thermostat bypass pipe.
5. Install the thermostat bypass pipe to the thermostat housing.

2. Install a NEW thermostat bypass pipe to water pump O-ring seal.
3. Install the thermostat housing crossover using NEW gaskets.
4. Install the thermostat housing crossover bolts and nuts.

Tighten the bolts/nuts to 21 N.m (15 lb ft).




5. Install the water pump inlet pipe bolts.

Tighten the bolts to 21 N.m (15 lb ft).




6. Install the fuel line bracket bolt at the thermostat housing crossover.

Tighten the bolt to 21 N.m (15 lb ft).




7. Install the turbocharger coolant return pipe hose.
8. Position the turbocharger coolant return pipe hose clamp.




9. Install the wiring harness bracket and bolts to the thermostat housing.

Tighten the bolts to 10 N.m (89 lb in).

10. Install the cooling fan pulley.
11. Install the power steering pump bracket.
12. Reposition the power steering pump and install the power steering pump bolts. Refer to Power Steering Pump Replacement (4.8L, 5.3L, 6.0L, and 6.2L) Power Steering Pump Replacement (6.6L) Power Steering Pump Replacement (4.3L).




13. Install the water outlet.
14. Connect the ECT sensor electrical connectors.
15. Install the front oil fill tube.
16. Install the generator bracket.




17. Connect the A/C compressor clutch electrical connector (2).
18. Connect the A/C cut out switch electrical connector (1).
19. Install the drive belt.
20. Connect the negative battery cables.
21. Fill the cooling system. Refer to Cooling System Draining and Filling (Static Fill) Cooling System Draining and Filling (Vac-N-Fill).
22. Install the air cleaner.