What was found
GEAR DISAGREE MASTER WARNING / INTERROGATED MDC AND FOUND B1 CODE 005968. PERFORMED OPERATIONAL TEST OF THE LANDING GEAR EXTENSION/RETRACTION SYSTEM IAW AMM 32-30-00-710-801-A01. LANDING GEAR RETRACTION ON ALL GEARS FAILED ON MULTIPLE ATTEMPTS. TROUBLESHOT ALL GEAR SYS/NO GEAR IAW FIM 32-31-00-810-803-A01 AND FOUND LANDING GEAR SELECTOR VALVE V20 UNSERVICEABLE. REMOVED AND REPLACED LANDING SELECTOR VALVE IAW AMM 32-32-10-000/400-801-A01. PERFORMED OPS TEST OF THE LANDING GEAR EXTENSION/RETRACTION SYSTEM FOUR TIMES IAW AMM 32-30-00-710-801-A01. OP TEST GOOD. NO LEAKS NOTED. NO FURTHER DEFECTS NOTED.