Process for manufacturing a plastic fuel tank equipped with a component, by molding a parison using a mold comprising two cavities and a core, the process comprising the mounting of a component around a needle or an oblong object attached to the core, the displacement of the needle or oblong object so as to deform the parison and pierce an opening into it, the needle or oblong object carrying the component with it in order to position the component in the opening, and the withdrawal of the needle/oblong object, leaving the component lodged in the opening.