GMC · Canada · Mod
GMC T70, Topkick 8500 +2 more: Brakes
Affects GMC T70, Topkick 8500, Topkick 7500, T80 · 2007 — about 101 vehicles.
The hazard
On certain trucks, the air compressor may not built enough air pressure to support the air brake system. If this condition were to occur while the vehicle is stationary (brake applied), the air brakes would remain applied and prevent the vehicle from moving. Should it occur while the vehicle is in motion, the rear spring parking brakes would engage, slowing the vehicle to a stop, and preventing it from being driven. Correction: Dealers will inspect the air compressor for its ability to build air pressure, and either modify the air compressor by eliminating the suppression valve or replace the air compressor assembly altogether.
What to do
Contact your dealer; the remedy details were not included in the filing.