Here's a step-by-step guide:
1. Preparation:
* Safety Gear: Wear safety glasses, gloves (nitrile or equivalent), and a respirator or dust mask. Old clothes you don't mind ruining are also recommended.
* Disconnection: Disconnect the fuel lines. This is crucial. Label the lines clearly to avoid confusion during reassembly. You'll need to relieve fuel pressure in the system, which may involve cracking a fuel line (do this outside and away from any ignition sources). Have rags ready to absorb any spilled fuel.
* Removal: Carefully remove the fuel tank from the truck. This will require disconnecting the fuel lines, the fuel sending unit (if applicable), and possibly straps holding the tank in place. Consult a repair manual for your specific truck model for detailed instructions. A helper is highly recommended, as fuel tanks are heavy.
* Emptying: Completely empty the tank as much as possible. Siphoning is an option, but be extremely careful. You can also use a shop vac with a liquid collection attachment designed for flammable materials. *Never use a shop vac without this feature.*
2. Cleaning the Tank:
Several methods exist, each with pros and cons:
* Commercial Tank Cleaner: This is the easiest and often most effective method. Many automotive parts stores sell tank cleaners designed to dissolve rust, varnish, and other debris. Follow the manufacturer's instructions precisely, paying close attention to safety precautions. This usually involves filling the tank with the cleaner, allowing it to soak for the recommended time, then rinsing thoroughly with clean water. You'll need to use plenty of water and possibly a pressure washer to ensure complete removal of the cleaner.
* Mechanical Cleaning: If the tank isn't severely rusted, you can use a long-handled brush, a chain with a weight inside the tank, or a tank cleaning tool (often available at auto parts stores) to manually scrub away loose debris. This is labor-intensive and less effective than chemical cleaning for significant rust or sediment.
* Water and Pressure Washing (After Mechanical Cleaning): After mechanical cleaning or chemical cleaning, use a pressure washer with a long wand attachment designed for tanks to thoroughly rinse the inside of the tank. Make sure the water pressure isn't too high to avoid damaging the tank.
3. Drying and Inspection:
* Thorough Drying: After rinsing, allow the tank to completely dry. You can use compressed air to help speed up the process, but be careful not to introduce any moisture or debris. Consider leaving the tank open to air out for several days.
* Inspection: Carefully inspect the tank for any signs of significant rust, holes, or damage. Small amounts of surface rust might be acceptable, but larger areas of rust or damage may require repair or replacement. A professional tank repair shop might be needed.
4. Reassembly:
* Installation: Once the tank is clean, dry, and inspected, reinstall it in the truck, following the reverse of the removal procedure. Reconnect the fuel lines, fuel sending unit (if applicable), and straps. Double-check all connections for leaks.
* Fuel Filter Replacement: It's highly recommended to replace your fuel filter after cleaning the tank to prevent any remaining debris from reaching the fuel pump or injectors.
Important Considerations:
* Rust: Severe rust can weaken the tank and lead to leaks. In this case, replacement is often the best option.
* Professional Help: If you're uncomfortable with any part of this process, it's best to consult a professional mechanic.
* Repair Manual: A repair manual specific to your 1973 Ford truck model is invaluable. It will provide detailed instructions and diagrams for removing and reinstalling the fuel tank and other components.
Cleaning a fuel tank is a potentially hazardous project. If you are not comfortable performing this task, take your vehicle to a professional mechanic. Remember to always prioritize safety and follow all manufacturer instructions for any chemicals used.
