The sudden failure of an inexpensive part can leave you and your vehicle stranded by the side of the road. This is especially true of the cooling system thermostat. The thermostat resides in between your engine and your radiator and acts as a temperature controlled engine coolant valve. If the valve fails, so does your cooling system and an overheated engine, and driver, often are the unfortunate end result. The good news is thermostats are inexpensive and relatively easy to replace.
Thermostat
Removal & Installation
1. Disconnect the negative battery cable.
2. Drain and recycle the engine coolant.
3. Remove the Power Steering reservoir support bracket.
4. Remove the upper radiator hose at the thermostat housing.
5. Remove 2 thermostat housing retaining bolts and remove the housing.
6. Remove the thermostat and O-ring from the lower intake manifold. Discard the O-ring.
To Install:
7. Clean the O-ring sealing surfaces.
8. Install a new O-ring, on the thermostat and position the thermostat in the lower intake manifold.
9. Place the thermostat housing on the lower intake manifold and install 2 retaining bolts. Tighten the bolts to 15-22 ft. lbs. (20-30 Nm).
10. Install the power steering reservoir support bracket.
11. Fill the engine cooling system.
12. Connect the negative battery cable.
13. Start the engine and allow it to reach normal operating temperature while checking for coolant leaks.
14. Road test the vehicle and check for proper engine operation.
15. Check the coolant level and add if necessary.
The thermostat is located right beside the intake manifold on the engine of a 1999 Ford F 150 XLT. The thermostat can be found by following the upper radiator hose.
Follow the large top radiator hose down to the water outlet on the engine ; that is where the thermostat is. Mark
At the lower end of the top rad hose within the water outlet. Mark
Follow the upper rad hose and at the engine is the housing that houses the thermostat. When replacing it make sure the spring goes toward the engine.
6 quarts with the filter change.
( 6 quarts with engine oil filter change ) according to the 1999 Ford F-150 Owner Guide for the 4.2 liter V6 engine
The 1999 Ford F-150 owners manual shows ( 6 quarts ) with engine oil filter change
On a 1993 Ford F-150 : Follow the top radiator hose from the radiator . Where it connects to the engine is the engine cooling thermostat
heater core is in back of the glove box
According to the 1999 Ford F-150 Owner Guide : With engine oil filter change : The 4.2 liter V6 engine takes ( 6 quarts )
For a 1999 Ford F-150 , 4.2 liter V6 engine : With engine oil filter change : ( 6.0 U.S. quarts / 5.7 litres of engine oil )
6 U.S. quarts with filter change