If you smell gas when you're in or around your car, chances are you have a gas leak. If upon visual inspection you see that the leak is coming from your gas tank, you need to fix it before you operate the car again. Not only is a leaky fuel tank costly due to the loss of fuel, it's a serious hazard that may lead to significant harm if the gas somehow ignites. Remember, this is a temporary fix --- you should have the car looked at as soon as possible by a qualified technician.
Drain any remaining fuel out of the gas tank. If possible, allow the car to run until there's less than a gallon in the tank. Remove the gas line from the tank with an open-end wrench and needlenose pliers. Allow the remaining gas to drain into a plastic container.
Unscrew the electrical connector from the gas tank. This connector is usually located behind the back bumper of the vehicle.
Place jacks under the fuel tank and loosen the nuts that secure the straps to the body of the car. Remove the fuel pipe and lower the gas tank.
Sand the damaged area of the tank. File off all the rust and remove any dirt and debris. Finely sand the area with an emery cloth after the rough sanding has been completed.
Apply fuel tank putty to the affected area. Refer to the manufacturer's instructions for mixing and application instructions. Allow to thoroughly dry for the recommended time and sand it down with emery paper. Prime and paint the tank to preserve the remaining metal and putty.
Connect the tank back to the car. Use jacks to jack it up into place. Tighten the nuts that strap the tank to the car's underbody. Attach the fuel line tubing and the electrical connector.
Test the tank by filling it with gasoline. Give it a few minutes, then check underneath for leaks.
