WARNING: This page is about a different car, the 2003 Mercury Sable and 2003 Ford Taurus. However, it is still accessible from the selected car via links, so may be relevant.
To connect, push both of the coupling ends together until the spring lock is in place.
Inspect and clean both coupling ends.
Lubricate the O-ring seals with engine oil.
Fig 1: Identifying O-Ring Seals Of Spring Lock Coupling