1. Gather Supplies:
* New Gas Cap Gasket: Make sure you get the correct gasket for your 1966 Mustang's gas cap. A local auto parts store should have them, or you can find them online. You might need the gas cap itself to ensure you get the right size.
* Screwdriver (Probably Phillips): This is needed to remove the gas cap.
* Small Flat-Head Screwdriver (Optional): Might be useful for gently prying up the old gasket if it's stuck.
* Clean Rags or Shop Towels: To clean up any spills or debris.
* Gloves (Optional): Always a good idea when working with automotive parts.
2. Remove the Gas Cap:
* Open the Fuel Door: Locate the fuel filler door on the side of your car and open it.
* Remove the Gas Cap: Unscrew and remove the gas cap from the fuel filler neck. Note the orientation of the gasket, if possible, in case it is a non-symmetrical design.
3. Remove the Old Gasket:
* Inspect the Gasket: Carefully examine the old gasket. It's usually a rubber ring. If it's brittle, cracked, or significantly deformed, replacement is necessary.
* Remove the Gasket: Gently pry the old gasket away from the gas cap. A small flathead screwdriver can be helpful for this, but be careful not to scratch the gas cap. You can also try using your fingers to peel it off. Sometimes it helps to loosen a corner first.
4. Install the New Gasket:
* Clean the Gas Cap: Clean the surface of the gas cap where the gasket sits. Use a clean rag to remove any dirt or debris.
* Position the New Gasket: Carefully position the new gasket into the groove on the gas cap. Make sure it's seated evenly all the way around. There might be small locating notches to help you align the gasket.
5. Reinstall the Gas Cap:
* Replace the Gas Cap: Screw the gas cap back onto the fuel filler neck, ensuring it's tightened securely. Don't overtighten.
Important Considerations:
* Gas Cap Type: There are variations in gas cap designs, especially across different years and models. While the process is generally similar, the exact details might vary slightly.
* Gasket Material: Ensure you use a gasket made of a material suitable for fuel applications.
* Tightening: Over-tightening the gas cap can damage it or the filler neck. Tighten it firmly but avoid excessive force. You should feel solid resistance, but there shouldn't be excessive pressure.
If you encounter any difficulties, consult a repair manual specific to your 1966 Mustang. Pictures of the process for your exact gas cap would be beneficial if you have trouble visualizing the steps. If you are uncomfortable performing this repair yourself, taking it to a mechanic is always an option.
