What was found
A/C HAD AN AIR TURNBACK INTO MSP DUE TO NOSE GEAR AIR GROUND DISAGREE DISPLAYED ON EICAS AFTER GEAR RETRACTION. REPLACED S10067 SWITCH, A/C TAKEOFF A/C HAD A SECOND AIR TURNBACK INTO MSP DUE TO STATUS MSG AIR GROUND DISAGREE. PERFORMED INDUCTANCE CHECK ON THE NOSE GEAR PROX SWITCHES S67 AND S68 PER FIM 32-9-3 ALL OK. FOUND NOSE GEAR STRUT OVERSERVICED WITH FLUID AND MAIN GEAR STRUTS LOW RESERVICED ALL GEAR STRUTS PER MM 12-15-1 AND 12-15-2.