What is the primary function of brake chambers in an air brake system?

The primary function of brake chambers in an air brake system is to convert the energy of compressed air into mechanical energy. When air is compressed into the brake chamber, it pushes a piston, which in turn applies force to the brake shoes or linings, resulting in the slowing or stopping of the vehicle. This conversion is essential for the functionality of air brakes, as it directly translates the energy from the compressed air into the mechanical action required to engage the brakes.

The other options do not accurately describe the role of brake chambers. Electrical power is not supplied through brake chambers; rather, electrical components in a braking system may have separate functions. Similarly, hydraulic fluid is part of a hydraulic brake system, not air brakes. Lastly, while air pressure is essential for an air brake system, the brake chambers specifically do not generate air pressure for the entire vehicle; they utilize already pressurized air to create the necessary mechanical force for braking.