What was found
FIRST LEG TEB-LGA NORMAL OPS. AFTER T/O FROM LGA LDG GEAR WOULD NOT RETRACT. NOSE GEAR NOT UP CAS POPULATED WE BROUGHT GEAR DOWN GOT 3 GREEN. TRIED GEAR AGAIN. SAME CAS NOW W NOSE DESPIN CAS. WE FOLLOWED QRH FOR THIS. DIRECTING US TO LDG GEAR FAILURE TO RETRACT CHECKLIST. COMPLETED THIS, DIVERTED SWF. MX C/A: PERFORMED LANDING GEAR HYDRAULIC SELECTOR / DUMP VALVE REMOVAL / INSTALLATION, LANDING GEAR CYCLING OPERATIONAL TEST, LANDING GEAR EMERGENCY EXTENSION SYSTEM FUNCTIONAL CHECK, HYDRAULIC SYSTEM SHUT - OFF VALVE (LEFT AND RIGHT) OPERATIONAL CHECK, HYDRAULIC SYSTEM RESERVOIR (LEFT AND RIGHT) SERVICING, LANDING GEAR EMERGENCY EXTENSION NITROGEN BLOW-DOWN BOTTLE SERVICING AND EMERGENCY LANDING GEAR SYSTEM LINES FLUSH. ALL WORK PERFORMED I.AW. GULFSTREAM G450 AMM 32-39-00, 12-33-00, 12-15-00, 29-15-00, 32-00-00 AND 32-30-03. ALL CHECKS WERE PERFORMED SATISFACTORILY. NO FURTHER DEFECTS NOTED. RII