During a shift, a loader operator experiences a sudden and complete loss of hydraulic power to all functions (lift, tilt, steer), but the engine continues to run normally. There are no warning lights on the dash, and the hydraulic fluid level is correct. What should the operator inspect first?

Question: During a shift, a loader operator experiences a sudden and complete loss of hydraulic power to all functions (lift, tilt, steer), but the engine continues to run normally. There are no warning lights on the dash, and the hydraulic fluid level is correct. What should the operator inspect first?

Answer options: ✅ The hydraulic pump drive coupling or main hydraulic pump fuse.

• The main hydraulic relief valve for being stuck open.
• The joystick control unit's electrical connections.
• Each individual hydraulic cylinder for internal leaks.

Correct answer: The hydraulic pump drive coupling or main hydraulic pump fuse.

Explanation: A complete and sudden loss of all hydraulic functions, while the engine runs, points to a failure at the primary source of hydraulic power or its initial delivery. The hydraulic pump drive, or a main fuse/breaker protecting the electric pump (if applicable), is the most likely single point of failure that would cut off all functions at once. Individual cylinder leaks or relief valve issues would typically affect specific functions or cause reduced pressure, not a complete system shutdown.