Intermittent stuck brake at FM1 car whentrain braking. ~~~~~ #1608 When B1 to coast, heavy air leak from solenoid coarse exhaust which causes stuck brake - replaced ACU. ACU-Old s/n: 1523-119.  New s/n: 1429-015. Not: 2123624 raised to RSW. Done by KoH B.S. 23/01/20.