Tools You'll Need:
* New thermostat: Make sure you get the correct one for your engine.
* New gasket: The old gasket should be replaced.
* Socket wrench set: Various sizes will likely be needed.
* Wrench set: For various bolts and possibly hose clamps.
* Pliers: Needle-nose pliers can be helpful.
* Drain pan: To catch coolant.
* Coolant: Enough to refill the system after the job is complete. Use the correct type specified for your Ranger.
* Funnel: To help refill the radiator.
* Jack and jack stands (highly recommended): This will give you better access and improve safety.
* Gloves: To protect your hands.
* Shop rags or paper towels: For cleanup.
Procedure:
1. Safety First: Let the engine cool completely before starting this job. Hot coolant can cause serious burns. If you're using a jack, ensure the vehicle is securely supported on jack stands.
2. Drain the Coolant: Locate the radiator drain petcock (usually at the bottom of the radiator). Place your drain pan underneath and carefully open the petcock to drain the coolant.
3. Locate the Thermostat Housing: The thermostat housing is typically located on the engine block, near the top of the engine. Its exact location varies slightly by engine. Consult your repair manual for its precise location.
4. Remove the Thermostat Housing: You'll need to remove some hoses and possibly bolts securing the housing. These will likely be held on with clamps. Carefully loosen these clamps (usually worm-gear clamps) and remove the hoses. Then, carefully remove the bolts holding the thermostat housing in place.
5. Remove the Old Thermostat: Once the housing is removed, the thermostat will be visible. Carefully remove the old thermostat and its gasket.
6. Inspect and Clean: Inspect the thermostat housing for any damage or debris. Clean it thoroughly.
7. Install the New Thermostat and Gasket: Install the new gasket onto the thermostat housing, ensuring it's properly seated. Then, carefully install the new thermostat into the housing, making sure it's oriented correctly (usually a small notch or arrow indicates the proper orientation).
8. Reassemble: Reinstall the thermostat housing, making sure all the bolts are tightened evenly and securely. Reconnect the hoses, ensuring the clamps are securely fastened.
9. Refill the Coolant System: Carefully refill the radiator with the correct type of coolant, checking your owner's manual for the proper mixture of coolant and water. Add coolant to the overflow reservoir as well.
10. Bleed the Air: Start the engine and let it run for a few minutes. Check for any leaks. The cooling system may need bleeding to remove air pockets. This often involves opening the bleed valve (if equipped) on the thermostat housing or radiator to allow air to escape. Consult your repair manual for proper bleeding procedure.
11. Check Coolant Level: Once the engine is cool, check the coolant level in the radiator and overflow reservoir, and top off as needed.
Important Considerations:
* Repair Manual: A repair manual specific to your 1999 Ford Ranger is invaluable. It will provide detailed diagrams and instructions specific to your engine and model.
* Engine Type: The exact procedure may vary slightly depending on whether you have a 2.3L, 2.5L, 3.0L, or 4.0L engine.
* Coolant Type: Use the correct type of coolant specified in your owner's manual.
* Safety: Always prioritize safety. Work in a well-ventilated area and wear appropriate safety gear.
This is a general guide, and the actual process may differ slightly. If you're not comfortable performing this repair yourself, it's best to take your vehicle to a qualified mechanic. Improperly installing a thermostat can lead to engine overheating and damage.
