TD5 Braking puzzle

Mucking around with the EGR vacuum pipes I disconnected all 3 attached to the EGR valve and took the disco for a run. There was no noticable change in braking performance even though one of the pipes is connected to a 'T' piece linked to the servo. Should this be the case or am I missing something ?

if you opened up pipes by removing them and not blocking ends up some vaccum will be lost