What is the reason for the jerk when releasing the brake to start an automatic transmission car?

[SanJames]

The reason for the jerk when releasing the brake to start an automatic transmission car is the presence of stubborn dirt and impurities inside, especially when dirt and impurities accumulate in the valve body, forming blockages that prevent effective regulation of oil pressure, leading to jerking, impact, and slipping issues. Here are some precautions to take when starting: 1. Shift gears after pressing the brake pedal and check if the gear selector lever is in the correct position; 2. When starting over bumps or steps, it is best to press the brake pedal with your right foot. While the car is stationary, slightly release the right foot while gently pressing the accelerator pedal, and immediately lift the right foot while lightly pressing the brake pedal when crossing the step to prevent severe shaking of the vehicle; 3. Do not let the engine speed be too high when starting; wait for the engine speed to drop before starting.