What was found
ON FLIGHT 3502 PACK 2 FAIL EICAS MESSAGE DID NOT HAVE ENOUGH FUEL TO CONTINUE ON TO CVG ELECTED TO DO AN AIR RETURN TO DFW DISC-SHORTLY AFTER TAKEOFF, NR 2 BLEED AND PACK VALVE CLOSED ANNUNCIATED ON THE EICAS. PER AOM; CYCLED BLEED VALVE AND PACK SEVERAL TIMES. UNSUCCESSFULLY. NR 2 PACK VALVE WOULD NOT STAY OPEN. AIRCRAFT REMOVED FROM SERVICE. REMOVED AND REPLACED BLEED HOSE AT DUAL TEMP CONTROL VALVE PACK OPERATION CHECK GOOD IAW EMB 140 AMM 21-20-00. AIRCRAFT RETURNED TO SERVICE.