For some good examples how to teach technical and mechanic concepts concerning maintenance check Out PS, The Preventive Maintenance Monthly. It's a series of US Army technical bulletins published since June 1951 as a monthly magazine with comic book-style art to illustrate proper preventive maintenance methods.

Comic Legend Will Eisner’s Work Influences Military Training http://www.military.com/video/off-duty/humor/comic-legend-wi...

Also check out the PS archives. It's one of Will Eisner's hidden gems.

http://dig.library.vcu.edu/cdm/landingpage/collection/psm