Which of these components is typically repaired by rebuilding?

Rebuilding a component typically refers to the process of disassembling it, repairing or replacing worn parts, and then reassembling it to restore functionality. Among the options provided, components such as hydraulic accumulators, vacuum check valves, and vacuum boosters are often subject to more specialized maintenance practices.

Hydraulic accumulators can sometimes be repaired, but they are often replaced as a whole if they fail. Vacuum check valves are usually simple devices; if they fail, replacement is more common than repairing. Vacuum boosters, which provide power assistance to the brake system, may have internal components that can be inspected and restored, but complete rebuilding is less common in practice due to the nature of their wear and potential complexity.

The choice indicating "none of these choices" reflects that none of the listed components are typically subject to a rebuilding process in a standard maintenance environment. In these cases, routine inspection may lead to replacement rather than rehabilitation, reinforcing the idea that the concept of rebuilding is not commonly associated with these specific components.