What was found
DURING TAKEOFF, RECEIVED AN EICAS MLG AIR/GROUND FAIL CAUTION MESSAGE AFTER GEAR RETRACTION. SEVERAL SECONDS LATER RECEIVED EICAS ENG 1-2 REVERSER DISAGREE CAUTION MESSAGE. ALL OTHER SYS SEEMED TO WORK PROPERLY. DURING CLIMB REFERENCED AOM V1 EMERGENCY CHECKLIST. CONTINUED TO DESTINATION AND DECLARED AN EMERGENCY. REQUESTED A VISUAL CHECK OF LANDING GEAR BY TOWER. ACFT LANDED WITHOUT INCIDENT. ACFT REMOVED FROM SERVICE. REMOVED AND REPLACED THE NOSE LANDING GEAR CHARGING VALVE IAW CMM 32-21-10. THE OPERATIONAL CHECK WAS GOOD. THE ARICRAFT WAS RETURNED TO SERVICE.