What was found
ON GEAR EXTENSION, RECEIVED GREEN LIGHTS FOR THE LT MAIN AND NOSE GEAR BUT THE RT MAIN INDICATED YELLOW FOR APPROX 20 SECONDS FOLLOWED BY A RED "UNSAFE" INDICATION FOR ABOUT 30 SECONDS. ALSO SHOWED THE RT ANTI-SKID SYS INOPERATIVE. RT MAIN GEAR LIGHT THEN TURNED GREEN AND THE ANTI-SKID INOPERATIVE LIGHT EXTINGUISHED. LANDED WITHOUT FURTHER INCIDENT AND DID NOT RUN THE EMERGENCY GEAR EXTENSION CHECKLIST. TROUBLESHOT SYS AND FOUND UPLOCK & DOWNLOCK PRESSURES ERRATIC & INCONSISTANT WITH LIMITS GIVEN IN MM 32-32-00. LANDING GEAR SELECTOR VALVE LEAKING INTERNALLY. REPLACED SELECTOR VALVE WITH REPAIRED UNIT IAW CMP 323002. OPS CHECK GOOD.