One problem related to brake master cylinder has been reported for the 2020 GMC Sierra 1500. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2020 GMC Sierra 1500 based on all problems reported for the 2020 Sierra 1500.
2020 GMC sierra slt VIN:1gtu9ded5lz310106 15,700 miles. Braking system failure at about 45mph on highway 78 in loganville, GA aproching an intersection with red light, vehicle seemed to loose all power braking. I stood with all I could on the pedal, and turned to avoid rear ending stopped vehicles, running into middle of the intersection before it stopped; no accident ! dealer is replacing master cylinder and booster braking system, along with computer system ugrade. My concern is the dealership and NHTSA is aware of this issue, yet no cease and desist driving directive has been issued !.