We don't know if Faber survives. In the last part of the novel Montag has escaped to the forest and the book people. Faber tells Montag that he will take a bus out of town. Montag states that he hopes Faber got away before the bombing. We don't really know what happen to Faber. Bradbury leaves the fate of most of the characters left in the city to our imagination. Since they see the city in rubble after the bombing we can assume that most of the population has been killed, but we don't know if that is the case. We also never really know if Faber got on the bus and escaped before the bombing.