Which of the following is NOT a function of a brake drum?

The correct answer identifies that containing brake fluid is not a function of a brake drum. Brake drums are primarily associated with drum brake systems, which operate using brake shoes that press against the inner surface of the drum to create friction and slow down or stop the vehicle.

Supporting the brake shoes is crucial as it ensures they have a solid structure to push against during braking. Dispersing heat is also an important function since braking generates significant heat, and the drum helps to manage that heat to prevent brake fade. Furthermore, in vehicles equipped with anti-lock braking systems (ABS), the brake drum provides a surface that interacts effectively with the braking system.

However, brake fluid containment occurs within the brake lines and master cylinder, not the brake drum, which is why this option is not a function of a brake drum.