The Ford Mustang fuel tank is located underneath the trunk. When you pour in gasoline, the fuel runs through a pipe from your gas nozzle to the tank. The neck consists of a spout slid into a rubber hose. The rubber hose is clamped to the fuel tank. When the neck goes, it is better to replace the whole assembly than attempt to repair it. The pieces are made from plastic and rubber and once cracked, the integrity is broken.
Locate the fuel filler neck behind the gas door. This will be a plastic tube that runs from the fuel door to the fuel tank.
Twist the gas cap off and place it to the side. There will be three screws around the base of the fill spout. Remove the screws with a Phillips head screwdriver. Discard the gasket that is between the lip of the spout and the fuel tank door.
Crawl underneath the vehicle and locate the other end of the hose. It will be clamped to the back of the fuel tank.
Unscrew the hose clamp with a flat head screwdriver. Pull the hose off the fuel tank.
Unbolt the bracket holding the neck to the frame. The bracket is hooked up to the inside of the frame just below the door. The bracket is held on by one bolt that tightens the neck to the frame. This will require a socket wrench. Pry the bracket out enough to pull the neck out of the bracket.
Pull the top of the neck out of the back of the gas door. The neck will slide out. The fuel filler neck is in two parts and can separate once you pull one end from the other.
Ensure the spout is pushed into the rubber hose. In the long run, you are better off to replace both, as these parts will show wear and tear over the period of time.
Connect the new neck/hose to the back of the fuel tank. Ensure the hose clamp is positioned on the hose before placing on the fuel tank. Tighten the hose clamp down to secure the hose in place.
Thread the neck through the bracket. Tighten the bracket with the socket wrench. The neck should be secured to the frame.
Push the gasket over the spout and position where the old gasket was. Ensure the holes on the gasket match up to the holes in the back of the fuel access panel.
Tighten the three screws with a Phillips head screwdriver. Ensure all three screws are snug.
