GMC Sierra Owners Manual
Park Brake and P (Park) Mechanism Check
When you are doing this check, the vehicle could begin to move.
You or others could be injured and property could be damaged.
Make sure there is room in front of the vehicle in case it begins to roll. Be ready to apply the regular brake at once should the vehicle begin to move.
Park on a fairly steep hill, with the vehicle facing downhill. Keeping your foot on the regular brake, set the parking brake.
• To check the parking brake's holding ability: With the engine running and the transmission in N (Neutral), slowly remove foot pressure from the regular brake pedal. Do this until the vehicle is held by the parking brake only.
• To check the P (Park) mechanism's holding ability:
With the engine running, shift to P (Park). Then release the parking brake followed by the regular brake.
Contact your dealer if service is required.