Why did the Hunter's truck stop working?

The truck stopped working because Rav pulled out the metal plug draining the engine oil. Engine oil is crucial for lubrication and cooling within the engine; without it, the engine can quickly overheat and sustain serious damage. When the engine runs without sufficient oil, parts can grind against each other, leading to a breakdown. This scenario demonstrates how critical it is for a vehicle to maintain proper oil levels to function effectively.

In this context, while a flat tire, running out of gas, or a dead battery could also cause a vehicle to become non-operational, they do not directly relate to the functioning of the engine at such a fundamental level as the loss of engine oil does. Pulling the metal plug creates an immediate and severe operational failure, highlighting the importance of oil in a truck's overall functionality.