What was found
AFTER TAKEOFF, GEAR HANDLE WAS SELECTED UP, NOSE WHEEL DID NOT RETRACT. "A" HYDRAULIC SYS EICAS MESSAGE ILLUMINATED. EMERGENCY CHECKLIST FOLLOWED, FLT DIVERTED. LANDED UNEVENTFUL. TROUBLESHOT TO A DEFECTIVE NOSE WHEEL STEERING CENTERING HOSE. NOSE WHEEL STEERING CENTERING HOSE WAS REPLACED, N2 SYS SERVICED AND HYDRAULIC SYSTEM SERVICED AND BLED. LEAK CHECK GOOD. ACFT WAS RETURNED TO SERVICE.