Canon iPF8400 Basic Manual page 37

iPF8400
3
If the ventilation duct (a) is dirty, use a damp cloth
that you have wrung out completely to wipe it
clean.
If the Carriage is obscuring the ventilation duct,
move the Carriage manually before cleaning the
duct.
4
Pull up the Carriage Cover to open it completely.
5
Pull the Printhead Fixer Lever forward all the way
to open it completely.
Basic Guide
Replacing the Printhead
37