One problem related to brake master cylinder has been reported for the 2005 Chevrolet Avalanche. The most recently reported issues are listed below.
Brake failure - loss of pressure/fluid. Brake lines from master cylinder to abs distribution block corroded and ruptured. Luckily, failure occurred just after returning home, maneuvering in the driveway. I have contacted gm to open a case and seek diagnosis/repair. Vehicle is in TN; not a high snow/corrosion area.