🔍 Key Concepts

• Axial piston variable stroke pump internal leakage paths • Purpose of the pump casing / housing in hydraulic pumps • Difference between internal recirculation of oil and loss of oil from the system

💭 Think About

• Think about where the oil that leaks between close‑fitting parts inside a hydraulic pump normally goes—does it usually leave the closed system or stay within it? • If there is controlled internal leakoff in a hydraulic pump, what is its usual effect on suction / discharge pressures versus on the oil inventory in the system? • Would normal internal leakage by itself be more likely to cause catastrophic mechanical damage, or a gradual change in efficiency or pressure?

✅ Before You Answer

• Clarify whether the pump casing is normally connected back to the return (low‑pressure) side of the system • Consider whether small internal leakoff is normal design leakage or necessarily a sign of failure • Check which answer choices imply oil leaving the closed system entirely versus simply recirculating within it