One problem related to anti-lock brakes fail has been reported for the 1999 GMC Sierra 1500. The most recently reported issues are listed below.
Brake lines failed on my 1999 gms sierra pick up. Had to be replaced at a cost of $2000. 00 +'s. Also anti lock braking has failed due to front sensor problem, gm wanted to replace front bearings and wheel hubs to fix this for $1100. 00 more,told them this was a recall they did in the past did not want to hear it. Had to remove fuse for anti lock braking, vehicle rides and brakes ok.