What is the very first step you should take when starting a tractor-trailer engine?

What is the very first step you should take when starting a tractor-trailer engine?

• A. Apply the parking brake
• B. Depress the clutch
• C. Turn the ignition switch/key on
• D. Apply the service brakes

Answer: (A)

Engaging the parking brake before starting is the safest first move because it locks the tractor-trailer in place, preventing any movement if the engine delivers torque or if the transmission is in gear. This is especially important for heavy vehicles where a roll or creep could injure someone or cause damage, even on a slight incline. Once the engine is running and you’re ready to move, you can proceed with the other steps and release the brake as appropriate.

Engaging the parking brake before starting is the safest first move because it locks the tractor-trailer in place, preventing any movement if the engine delivers torque or if the transmission is in gear. This is especially important for heavy vehicles where a roll or creep could injure someone or cause damage, even on a slight incline. Once the engine is running and you’re ready to move, you can proceed with the other steps and release the brake as appropriate.