Thermostat: Service and Repair

Engine Coolant Thermostat Replacement

Removal Procedure

1. Partially drain the cooling system. Refer to Cooling System Draining and Filling (GE 47716) (Cooling System Draining and Filling (GE 47716))Cooling System Draining and Filling (Static Fill) (Cooling System Draining and Filling (Static Fill)).
2. Remove the upper intake manifold. Refer to Intake Manifold Replacement (Intake Manifold Replacement).
3. Disconnect the surge tank outlet pipe from the thermostat. Refer to Radiator Surge Tank Outlet Hose/Pipe Replacement (Radiator Surge Tank Outlet Hose/Pipe Replacement).




4. Remove the coolant pipe/thermostat housing bolt (2).
5. Remove the coolant pipe upper bolt (3).
6. Remove the coolant inlet pipe (4) from the thermostat.




7. Remove the thermostat bolts (1).
8. Remove the thermostat (2) and discard the thermostat seal (3).

Installation Procedure




1. Install the thermostat (2) with a NEW thermostat seal (3).

Caution: Refer to Fastener Caution (Fastener Caution).

2. Install the thermostat bolts (1) and tighten to 10 Nm (89 lb in).




3. Install the coolant pipe (4), NEW seal, and fasteners (2 and 3). Refer to Engine Coolant Inlet Pipe Replacement (Service and Repair).
4. Connect the surge tank outlet pipe to the thermostat. Refer to Radiator Surge Tank Outlet Hose/Pipe Replacement (Radiator Surge Tank Outlet Hose/Pipe Replacement).
5. Install the upper intake manifold. Refer to Intake Manifold Replacement (Intake Manifold Replacement).
6. Fill the cooling system. Refer to Cooling System Draining and Filling (GE 47716) (Cooling System Draining and Filling (GE 47716))Cooling System Draining and Filling (Static Fill) (Cooling System Draining and Filling (Static Fill)).