TC reported air dryer fault. ~~~~~ 3547 TC reported air dryer fault. CE monitor:3547 MR 10bars No air dryer fault found.  3547 air dryer air inlet pipe coupling air leaking. Resealed the pipe coupling & air leak - OK. As preventive measures, replaced the air filters & the micro mesh filter. Funtion test air dryer change-over timing about 2 mins - OK. Air compressor cut-in 8.4 bar, cut-out 10.5 bar. Air leak test 0.4 bar/5 min. Monitor for 3 hours - OK.  Wong/Shamil 44831