Fuel tank apparatus and related methods are described. An example method includes placing a first end of a flexible coupling through an access opening formed on a wall of a fuel tank and into a first end of a guide positioned in a cavity of the fuel tank; feeding the first end of the flexible coupling in a first direction through the guide and away from the access opening; redirecting the first end of the flexible coupling towards the access opening by continuing to feed the flexible coupling the first direction; coupling a first fuel component to the first end of the flexible coupling when the first end of the flexible coupling is accessible via the access opening; and directing the flexible coupling in a second direction opposite the first direction via the guide to couple the first fuel component in the cavity of the fuel tank at a position away from the access opening.