What is the purpose of a relief valve in the hydraulic system?

• A. To limit system pressure, preventing component damage by routing excess fluid back to the reservoir.
• B. To increase pressure during braking.
• C. To monitor temperature.
• D. To drain fluid during maintenance.

Answer: (A)

A relief valve protects the hydraulic system by limiting pressure. It is set to open when the system pressure reaches a safe maximum, allowing excess fluid to return to the reservoir. This dumping of fluid prevents overpressure that could damage components such as hoses, seals, pumps, and actuators, ensuring braking remains within its designed pressure range. It isn’t about increasing pressure during braking—that function comes from the pump and control valves—nor is it for temperature monitoring or draining fluid during maintenance.