There is one valve that is used to add refrigrant. But you had better not add Freon. Freon is R12 and your vehicle's A/C system does not have Freon (R12) as a refrigrant. More than likely it uses R134a.
The 2014 Ford Expedition has 24 valves.
The 2013 Ford Expedition has 24 valves.
The 2009 Ford Expedition has 24 valves.
The 2010 Ford Expedition has 24 valves.
The 2001 Ford Expedition has 16 valves.
The 2008 Ford Expedition has 24 valves.
The 2005 Ford Expedition has 24 valves.
The 2004 Ford Expedition has 16 valves.
The 2002 Ford Expedition has 16 valves.
The 2012 Ford Expedition has 24 valves.
The 2006 Ford Expedition has 24 valves.
The 2003 Ford Expedition has 16 valves.