As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 902 - MEX-MTY - AIRCRAFT RETURN TO GATE DUE TO CENTRAL AND LEFT HYDRAULIC SYSTEM RSVR LIGHT CAME ON. SUPPLY LINES AND DEPRESSURIZATION VALVES WERE CHECKED NO DAMAGE WAS FOUND. NITROGEN SYSTEM WAS SERVICED AND WAS TESTED IAW MM 29-11-00. DURING OVERNIGHT SERVICE, CHECKED THE LEFT HYDRAULIC SYSTEM IAW MM 29-30-00, TESTS OK. (M)