What was found
EMERGENCY UPLOCK RELEASE ACTUATOR, PN WTC 2215-1, WAS ORIGINALLY REPLACED BECAUSE OF LEAK (HYD) AT ROD END. WHEN 'NEW' PART WAS INSTALLED (SAME P/N), IT LEAKED FROM END CAP. AFTER THIS, TWO OTHER ACTUATORS WERE TRIED WITH SAME RESULTS. THEY LEAKED WHILE PERFORMING MAIN/NOSE LANDING GEAR OPERATIONAL CHECKS. PIPER P/N 551 968. S/N'S AFFECTED: WTC1072; WTC1190; WTC1202; WTC1268; WTC1317; WTC1338.