Should the Brake Be Fully Depressed When Shifting an Automatic Transmission?
3 Answers
When shifting an automatic transmission, the brake should be fully depressed. The function of the brake is to reduce speed or bring the vehicle to a stop. Its working principle involves converting the kinetic energy of the moving vehicle into heat energy through friction between the brake pads and brake drums, as well as between the tires and the ground, thereby slowing down or stopping the car. Causes of brake failure include: 1. Impurities in the master brake cylinder or poor sealing; 2. Failure of the vacuum booster pump; 3. Contaminated brake fluid; 4. Leakage in the master or slave brake cylinder; 5. Air leaks in the air reservoir or pipeline connections; 6. Severe overloading; 7. Carbonization of the brake drum; 8. Insufficient brake fluid in the master cylinder; 9. Wear of the master brake cylinder piston.
I've been driving automatic transmission cars for over a decade, and I always make it a habit to press the brake pedal all the way down when shifting from park to drive, such as from P to D or R. Why? Because it ensures the car won't move unexpectedly, especially on slopes or uneven surfaces. There's a safety lock on the gear shift lever that only releases when the brake is fully depressed. If you don't press it deep enough, the gear might not shift properly or get stuck. I've seen people shift gears with only a partial brake press, causing the car to lurch forward suddenly, which is terrifying. Technically, it's not always necessary to press the brake all the way down, but doing so is the safest habit to avoid potential accidents. Safety comes first when driving, and developing this habit gives peace of mind whether on flat roads or slopes. Additionally, regular checks of the brake system and sensors are crucial—don't overlook maintenance.
When I first started learning automatic transmission, the instructor strictly emphasized that the brake must be fully depressed when shifting gears. He said beginners are most prone to making mistakes—either not pressing hard enough or forgetting to press at all—which could cause the car to suddenly lurch forward and lead to an accident. I remember during my first practice session, when shifting from Park to Reverse, I didn’t press the brake deeply enough, and the gear lever wouldn’t budge—it was quite embarrassing. Later, I learned that pressing the brake pedal to a certain point triggers a Boolean switch, unlocking the transmission. While it’s not always necessary to press the brake to its deepest point, developing the habit of pressing it firmly is essential, especially when starting on a slope. At the same time, I recommend practicing this action regularly to avoid mistakes under stress. The car is our travel companion, and safe operation is the top priority.
