They are rubber and if they leak they need to be replaced not repaired. In most cases changing out a bag is not to big of a job. most of the time 2-3 bolts top and bottom and the air line.
2012 Essex 4544 2011 Jeep JK, M&G Braking, 2014 MTI 27' Hog Hauler, Wireless brake control, 2006 Ultra & 1989 Springer, 2003 Harley-Davidson
FLHR Road King Anniversary