What is the normal hydraulic reservoir quantity?

• A. 0% to 25%
• B. 45% to 85%
• C. 25% to 50%
• D. 90% to 100%

Answer: (B)

Hydraulic reservoir quantity is about having enough fluid in the system to cover the pump’s suction needs and to allow for thermal expansion, while not overflowing or wasting space. The normal level sits in a mid-range: far enough from the bottom to prevent air ingestion and pump cavitation, but not so full that heat expansion could push fluid out or put strain on the venting system. This balanced position gives a reserve for peak demand and keeps the hydraulic system stable during normal operation. That mid-range level is why the best answer is the mid-range option.