Install printer
[embed_url: https://raw.githubusercontent.com/panticz/installit/master/hardware/install.brother-mfc-7320.printer.sh]

Install scanner
[embed_url: https://raw.githubusercontent.com/panticz/installit/master/hardware/install.brother-mfc-7320.scanner.sh]

Scanner
First POWER OFF your Brother MFC-7320
http://www.panticz.de/sites/default/files/scripts/install.brother-mfc-7320.scanner.sh
Now you can POWER ON your Brother MFC-7320 again
Go Applications > Graphics > Simple Scan

Fax
not tested yet, see: http://wiki.ubuntuusers.de/Brother/Fax

Links
http://wiki.ubuntuusers.de/Brother/Drucker
http://wiki.ubuntuusers.de/Brother/Scanner
http://wiki.ubuntuusers.de/Brother/Fax
http://welcome.solutions.brother.com/bsc/public_s/id/linux/en/download_prn.html#MFC-7320
http://welcome.solutions.brother.com/bsc/public_s/id/linux/en/download_scn.html