Safety First:
* Coolant is toxic. Wear gloves and eye protection. Work in a well-ventilated area.
* The coolant will be hot if the engine has recently run. Let the engine cool completely before starting. This could take several hours.
* Use jack stands. Never work under a vehicle supported only by a jack.
Tools and Materials:
* New coolant: Use the correct type specified in your owner's manual (usually a 50/50 mix of coolant and distilled water). Get enough to completely flush the system.
* Drain pan: Large enough to hold several gallons of coolant.
* Wrench(es): The size(s) needed will depend on your specific vehicle, but likely include a socket or wrench to remove the drain plug(s) from the radiator and engine block.
* Funnel: To help pour the new coolant into the radiator.
* Hose clamps (if replacing hoses): And the correct tools for tightening them.
* New radiator cap (optional but recommended): A worn cap can affect system pressure.
* Gloves and eye protection: Essential for safety.
* Clean rags or shop towels: To clean up spills.
* Optional: Coolant flush kit: These can help ensure a more thorough cleaning of the cooling system.
Procedure:
1. Locate the radiator drain petcock: This is usually located at the bottom of the radiator.
2. Place the drain pan under the radiator: Position it to catch the coolant.
3. Open the radiator drain petcock: Slowly open the petcock to allow the coolant to drain into the pan. Be cautious as it will be hot if the engine wasn't completely cool.
4. Locate the engine block drain plug: This is often located on the engine block near the bottom. Access may require removing some undercarriage components. Refer to your owner's manual. Place a drain pan underneath.
5. Open the engine block drain plug: Carefully remove the plug to drain the remaining coolant from the engine block.
6. Close the drain plugs: Once the coolant has drained, replace and tighten both the radiator and engine block drain plugs.
7. Open the radiator cap: Carefully remove the radiator cap (after the engine has cooled completely).
8. Flush the cooling system (optional but highly recommended): If using a coolant flush kit, follow the manufacturer's instructions. Otherwise, you can use a garden hose to flush the system. Connect the hose to the radiator inlet (upper hose connection) and run water through until it runs clear from the drain petcock.
9. Re-fill the radiator: Use a funnel to carefully add the new 50/50 coolant mixture to the radiator, filling it to the specified level (usually indicated on the radiator).
10. Start the engine: Run the engine for 15-20 minutes to allow the thermostat to open and circulate the coolant. Monitor the coolant level and add more if necessary.
11. Check for leaks: Inspect the system for any leaks around the drain plugs, hoses, and the radiator cap.
12. Allow the engine to cool: Let the engine cool completely before checking the coolant level again and adding more if needed.
13. Check the coolant level regularly: Check the coolant level regularly, especially during the first few days after the change.
Important Considerations:
* Air pockets: Air pockets in the cooling system can cause overheating. Make sure to bleed the air from the system according to your owner's manual instructions. Often this involves opening the bleed valve (if equipped) or squeezing upper radiator hose to release air.
* Hose condition: While you're working, inspect your hoses for cracks, bulges, or other signs of wear. Replace any damaged hoses.
* Thermostat: Consider replacing the thermostat at the same time. A malfunctioning thermostat can lead to overheating.
* Professional help: If you are uncomfortable performing this task yourself, it's best to take your vehicle to a qualified mechanic.
This guide provides a general overview. Always consult your owner's manual for specific instructions and torque specifications for your 1998 Ford Expedition. Improper coolant maintenance can lead to engine damage.
