Some JD filters come with a plastic funnel type arrangement that screws into the centre hole blanking it of and leaves the outer holes open. So simple to then just fill before fitting. The fuel or oil then takes the same route as when in normal operation and is filtered.Do you pre-fill oil filters? Some say it causes more contamination then problems associated with being empty.
Diesel same thing - but you have to fill them, so do you use a filtered source to fill them? Or plug the center and fill from the outside of element?