Thermostat: Service and Repair

REMOVAL

1. Remove the under cover.

CAUTION: Never remove the radiator cap while the engine is hot. Removing the radiator cap from a hot engine could result in a serious burn. Wrap a thick cloth around the cap when removing it.

2. Remove the radiator cap.
3. Open the drain cock and drain the coolant into a suitable, clean container. If not contaminated, save drained coolant for re-use.
4. Remove the thermostat cover by removing the two nuts that secure it. Discard the gasket.
5. Remove thermostat.
6. Test the thermostat.






TESTING
1. Immerse the thermostat and a suitable thermometer into a container of water.
2. Gradually heat the water and verify the following:
Initial Opening:
Sub valve: 182-188°FR (83-87°C).
Main Valve: 188-193°F (87-89°C).
Full Open: 212°F (100°C).
Full Open Lift (Minimum):
Sub Valve: 0.06 inch (1.5 mm).
Main Valve: 0.31 inch (8.0 mm).

INSTALLATION

1. Clean the thermostat cover mating surfaces and replace the gasket if required.
2. Allow the thermostat to dry and install in reverse order of removal, making certain the jiggle pin is at the top or forward.

3. Install a new gasket with the seal print side facing the thermostat housing.
4. Install the thermostat cover.
Tightening torque: 14-22 ft. lbs. (19-30 Nm).

5. Close the drain cock.
6. Refill the cooling system with the uncontaminated, reserved coolant or replace with new coolant. See coolant specifications for the proper mixture for the degree of protection desired:
Cooling system capacity: 7.9 quarts (7.5 liters).

7. Install the radiator cap.
8. Start the engine and allow it to come to operating temperature.
9. Inspect for leaks around the thermostat cover gasket.
10. Install the under cover.