Brake question

can anyone help me. on my 200 disco there is a T on the black vaccum pipe that comes off the servo unit and goes to the vaccum pump on the engine.
Im asking this as the T peice has nothing on it and im not sure if it should have. im guessing that since there is nothing connected to the T off then the servo wont be working properly??
what should conect to this T peice

ive just lookied at some pics of inside a disco engine bay there is a pipe thay should come off the servo vaccum pipe but i dont no what it conects to. can anyone have a look at theres??