What was found
(CAN) ON APPROACH, GEAR DID NOT EXTEND NORMALLY ON FIRST ATTEMPT, SECOND ATTEMPT HAD SAME RESULT. CREW ELECTED TO CARRY OUT GO AROUND. LANDING GEAR CONTROL LEVER REPLACED AND TESTED IAW MM 32-31-11-400, MLG ISOLATION SAFETY VALVE (85GA) REPLACED IAW MM 32-31-17. MLG. EXTENDED AND RETRACTED SEVERAL TIMES IAW MM 32-31-00-710-801, CHKD. SERV. REMOVE UNI 32-30-0482C1024AC 001 FISOS: NINSTALLUNI 32-30-0482 FTN 1341Q9 AC 001REMOVE UNI 32-30-0513 FTN 5Y25Z5 AC FI SOS: N INSTALL UNI 32-30-0513FTN 55656R AC.