A connector has first and second connector units, each unit incorporating an oil-filled chamber housing one or more contact elements to be joined. At least one connector unit has a face seal assembly which seals the forward end of the contact chamber in the unmated condition. The face seal assembly comprises three elements. One element is an annular elastomeric seal situated radially outward. The two other elements are inner seal elements which are pressed together radially to form a substantially disc-like shape. The resulting disc-like shaped seal fills the central, circular end face opening of the outer annular seal. As the connector units are mated, elements of the elastomeric face seal assembly are displaced, one axially, and others both axially and radially, creating an opening between the oil-filled chambers that is sealed from the outside environment.