What is the normal hydraulic reservoir quantity?

• A. 5-15%
• B. 25-45%
• C. 45-85%
• D. 90-100%

Answer: (C)

Normal hydraulic reservoir quantity is kept in the middle of the capacity, typically about 45% to 85%. This range provides enough fluid for the pumps to feed the system and maintain pressure, while leaving space for fluid expansion as the system heats and for any air that may accumulate. If the level gets too low, the pump can cavitate or starve for fluid, reducing actuation and system reliability. If it gets too high, expansion can cause venting or overflow, which can lead to contamination or pressure regulation issues. Sticking within this range helps ensure consistent performance across temperature changes and operation cycles.