A technician has completed a repair on a hydraulic cylinder on a piece of articulated equipment. Before connecting lines and testing, they must ensure the system is depressurized. The service manual specifies a sequence of operating control levers on the machine with the engine off to relieve pressure. What is the primary reason for this specific procedure?

Question: A technician has completed a repair on a hydraulic cylinder on a piece of articulated equipment. Before connecting lines and testing, they must ensure the system is depressurized. The service manual specifies a sequence of operating control levers on the machine with the engine off to relieve pressure. What is the primary reason for this specific procedure?

Answer options: ✅ To ensure all residual hydraulic pressure from trapped fluid in lines and actuators is safely dissipated.

• To verify that the hydraulic control valves are not stuck or seized.
• To lubricate the internal components of the hydraulic system before startup.
• To check for any leaks that may have developed during the repair process.

Correct answer: To ensure all residual hydraulic pressure from trapped fluid in lines and actuators is safely dissipated.

Explanation: Manually operating control levers with the engine off on a hydraulic system is a common procedure to 'cycle' the system and relieve any stored or residual pressure within the hydraulic lines, cylinders, and accumulators, preventing sudden, uncontrolled movement or fluid release when components are worked on. It is not primarily for valve testing, lubrication, or leak detection at this stage.