What was found
ON FLIGHT 4318 THE CREW REPORTED THAT ON TAKEOFF THEY RECEIVED A BLEED NR 1 LEAK MESSAGE. THE CREW DECLARED AN EMERGENCY AND RETURNED TO ORD. THE AIRCRAFT LANDED WITHOUT INCIDENT. THE AIRCRAFT WAS REMOVED FROM SERVICE. REMOVED AND REPLACED O-RINGS AND SLEEVES AT JOINT 17 IN CARGO COMP AS PER ETN-EM-36-048 IAW EMB-145 AMM 36-11-09. LEAK CHECK GOOD. ALSO REMOVED AND REPLACED THE BLEED NR 1 T TUBE ASSEMBLY AT JOINT 19 IAW EMB-145 AMM 36-11-09. THE OPERATIONAL CHECK WAS GOOD. THE AIRCRAFT WAS RETURNED TO SERVICE.