Which fluids should you check during a pre-operation inspection?

• A. Engine oil, hydraulic oil, coolant, fuel level, transmission oil, and separator fluids.
• B. Engine oil and brake fluid only.
• C. Transmission oil only.
• D. Coolant and windshield washer fluid.

Answer: (C)

In a pre-operation inspection, the focus is on fluids that directly affect the machine’s ability to operate safely from the start. Transmission oil is the key concern here because it lubricates and cools the gearbox, helping prevent wear and overheating as soon as the machine begins to move or work hard. If the transmission oil level is low or its condition is poor, the transmission can suffer damage quickly under load, which makes checking this fluid a high-priority step before starting. In this exam context, that emphasis on transmission oil reflects the importance of ensuring the drivetrain is properly lubricated and ready to perform, which is why this option is considered the best answer.