Yes, a faulty brake cylinder can indeed cause your car to jerk when driving or coming to a stop. The brake cylinder is a key component of the brake system responsible for applying hydraulic pressure to the brake pads or shoes, which then create friction against the rotors or drums to slow down or stop the vehicle.

If the brake cylinder is malfunctioning or failing, it can lead to several issues that can cause jerking or uneven braking. Here are a few possibilities:

1. Brake Fluid Leak: A leaking brake cylinder can result in reduced hydraulic pressure in the brake system. This can cause inconsistent brake application, resulting in jerking or sudden movements when you press the brake pedal.

2. Brake Dragging: A malfunctioning brake cylinder can cause the brakes to drag, meaning they do not fully release after you release the brake pedal. This can lead to increased friction and uneven braking, causing the car to jerk when driving or coming to a stop.

3. Uneven Brake Application: If one side of the brake cylinder is working improperly, it can cause uneven pressure on the brake pads or shoes. This can result in uneven braking performance, leading to jerking or pulling to one side when applying the brakes.

4. ABS Malfunction: In some vehicles, the brake cylinder is integrated with the Anti-lock Braking System (ABS). If the ABS module or related components in the brake cylinder are faulty, it can affect the braking system's overall performance and cause jerking or erratic behavior while braking.

It's important to note that without a professional diagnosis, it can be challenging to determine the exact cause of the issue. If you suspect a problem with your brake cylinder, it is highly recommended to have your vehicle inspected by a qualified mechanic. They will have the necessary tools and expertise to diagnose the problem accurately and perform any needed repairs or replacements.