TC reported unusual sound at FDT and FM1undercarriage. Staff (MSP) board T229 from MSP1 to MRB1 che cked and confirmed no unusual sound hear atboth FDT and FM 1. Staff (SOM) board T226 from SOM to ORC checked and confir ERS-13 ~~~~~ 3528 Need to C/O Air dryer Air Dryer c/o due to Air Dryer choke and cause air compressor air back flow and trigger air compressor safety v/v blowing.Purge out MR tank to clear the moisture.Function test ok and change over ok. #3528 Air Dryer- Old s/n: 351580281 New s/n: 015 14349 Not: 2427025 raise to RSW. Done by Sanip/Koh  14/10/22 TC reported unusual sound at FDT and FM1     Check the above mention reported undercarriage and side check ok.No abnormal and unsual sound accept #3528 safety v/v blow.Limited movement several times and check brake status ok.Air leak test ok. 0020 raise for Air Dryer c/o. Done by Saini/Asruddin. 13/10/22