The jerking forward during braking is likely caused by one or more of the following:
* Brake system issues: This is the most probable cause. Problems like:
* Uneven brake pad wear: If one brake is significantly weaker than others, the car can pull or jerk.
* Worn or damaged brake rotors or drums: Similar to uneven pads, this can lead to inconsistent braking force.
* Faulty brake calipers or wheel cylinders: These components can stick or seize, causing uneven braking.
* Hydraulic problems: Leaks or air in the brake lines can cause inconsistent brake pressure.
* Driver error: While less likely to cause consistent jerking, aggressive braking or pumping the brakes (except in specific ABS situations) can lead to a jerky stop.
* Engine braking (in manual transmissions): In vehicles with manual transmissions, quickly downshifting while braking can cause a jerking sensation. This is more likely to be felt as a sudden deceleration rather than specifically a forward lurch.
In short: If your car is jerking forward while braking, you should have your brake system inspected by a qualified mechanic as soon as possible. This is a safety issue that shouldn't be ignored.