Which of the following checks is most critical before operating machinery?

Checking the fuel level is critical before operating machinery because it directly impacts the machine’s ability to function. If the fuel level is low or empty, the machine cannot operate, which can lead to unexpected interruptions or failures during operation. Ensuring that there is sufficient fuel allows operators to work efficiently without the risk of being stranded or needing to stop frequently to refuel.

While checking the horn, wheel alignment, and paint condition have their importance, they do not directly affect the immediate operation of the machine in the same way as fuel does. A functional horn is for safety communication, proper wheel alignment contributes to handling efficiency and wear, and paint condition might indicate maintenance needs. However, without fuel, the machine simply cannot run. Therefore, monitoring the fuel level should be a primary focus before beginning any operation of machinery.