Thermostat: Service and Repair

ENGINE COOLANT THERMOSTAT

REMOVAL
1. Disconnect negative cable.

WARNING: DO NOT REMOVE PRESSURE CAP WITH THE SYSTEM HOT AND UNDER PRESSURE BECAUSE SERIOUS BURNS FROM COOLANT CAN OCCUR.

2. Drain cooling system.





3. Remove radiator lower hose from thermostat housing (1).
4. Remove nuts from heater tube flange studs.
5. Loosen starter bolt at heater tube bracket.
6. Pull heater tube out of thermostat housing and position out of the way.
7. Remove bolt (3) and two studs.





8. Remove thermostat housing (1), O-ring (2) and thermostat (4).
9. Remove thermostat housing bolts (3).

INSTALLATION
1. Clean gasket sealing surfaces.

NOTE: Install thermostat with the bleed valve located at the 12 o'clock position, between tabs on seal.





2. Install thermostat (5) and seal (2) into thermostat housing (1).
3. If removed, install two studs.
4. Install thermostat, thermostat housing (5) and O-ring and bolt (4). Tighten attaching bolts to 12 Nm (105 inch lbs.).
5. Lubricate new heater return tube O-ring with coolant.





6. Position heater return tube flange over two studs. Install nuts. Tighten retaining nuts (3) to 6 Nm (53 inch lbs.).
7. Tighten starter bolt to 54.3 Nm (40 ft. lbs.).
8. Connect the lower radiator hose to the thermostat housing. Install hose clamps.
9. Refill cooling system.
10. Connect negative cable.