If you have mechanical experience, installing a new fuel tank in your Nissan Altima isn't a difficult job, but the key is to be aware of safety at all times. If you take your time, you can save money by installing a new fuel tank yourself.
Disconnect the negative battery cable before you begin, and be sure that the tank is depressurized. Drain the fuel from the tank into a suitable gas can.
Remove the access plate to the fuel pump, located under the rear seat. Label all of the fuel hoses and electrical harnesses with a marker to make it easier to replace them when you've finished, and disconnect them.
Raise the rear of the vehicle with a jack and support it safely on a jack stand. Block the rear wheels to keep them from rolling. Label all fuel lines to make them easier to replace. If your Nissan Altima is a 240SX model, disconnect the exhaust tube, differential carrier, rear suspension member and drive shaft.
Disconnect the vent hose and fuel filler hose, and take off the tank's protector assembly.
Support the tank with a floor jack and remove the retaining bolts on the fuel tank band. Carefully lower the tank out of the vehicle.
Put the new tank on the floor jack and raise it carefully into the vehicle. Reconnect all the fuel tank and engine components in the reverse order in which they were removed, and lower the rear of the vehicle.
Add a few gallons of fuel to the tank, repressurize the system and check it for leaks.
