Our company L300FB ran out of oil the other day. So we need to have it overhauled. According to the driver, he checked the oil before using it. He said it ran out of oil because loose thread yung drain bolt and the oil drained out. I find it hard to belive. I think he just forgot to check the oil before driving. What do you think, is his story possible? Can the mechanic check if the drain bolt is really defective?