GASOLINE ENGINES
Remove or Disconnect (Figures 18 through 20)
1. Drain the cooling system until the radiator coolant level is below the thermostat.
2 . Bolts or studs.
3. Coolant outlet.
4. Thermostat from its housing.
5. Gasket (if necessary).
Clean
*Thermostat housing and coolant outlet sealing surfaces.
Install or Connect (Figures 18 through 20)
1. Thermostat in its housing.
2. New gasket into position (if necessary).
3. Coolant outlet.
4. Bolt and studs.
Tighten
Bolts and studs to 28 N.m (21 Ibs. ft.) on 4.3L, 5.0L, and 5.7L engines.
• Studs to 37 N.m (27 Ibs. ft.) on 7.4L engines.
5. Fill the cooling system.
6. Start the engine and run with the radiator cap removed until the radiator upper hose becomes hot (thermostat is open).
7. With the engine idling, add coolant to the radiator until the coolant level reaches the bottom of the filler neck.
8. Radiator cap to the radiator, making sure the arrows line up with the overflow tube.
9. Check for leaks.
DIESEL ENGINES
Remove or Disconnect (Figure 21)
1. Upper fan shroud. Refer to SECT ION 6B2.
2. Drain the cooling system until the radiator coolant level is below the thermostat.
3. Engine oil dipstick tube brace and the oil fill brace.
Refer to SECTION 6A6.
4. Upper radiator (inlet) hose.
5. Bolt, stud, and the coolant outlet.
6 . Gasket.
7. Thermostat from its housing.
Clean
– Thermostat housing and coolant outlet sealing sur faces.
Install or Connect (Figure 21)
1. Thermostat into its housing.
2. Gasket into position.
3. Coolant outlet.
4. Bolt and stud.
Tighten
• Bolt and stud to 42 N.m (31 Ibs. ft).
5. Upper radiator (inlet) hose.
6. Engine oil dipstick tube brace and the oil fill brace.
Refer to SECTION 6 A6 .
7. Upper fan shroud. Refer to SECTION 6B2.
8. Fill the cooling system.
9. Start the engine and run with the radiator cap removed, until the upper radiator hose becomes hot (thermostat is open).
10. With the engine idling, add coolant to the radiator until the coolant level reaches the bottom of the filler neck.
11. Radiator cap to the radiator, making sure the arrows line up with the overflow tube.
12. Check for leaks.