How does air in hydraulic fluid affect system performance?

How does air in hydraulic fluid affect system performance?

• A. Air compresses, causing a spongy feel, reduced responsiveness, and potential cavitation; purge and filtration are needed.
• B. Air increases fluid density and improves response.
• C. Air reduces viscosity and smooths motion.
• D. Air cools the system and improves efficiency.

Answer: (A)

Air in hydraulic fluid makes the system more compressible, which disrupts the normally firm, immediate transmission of force through the fluid. Those air bubbles act like tiny cushions, so the actuator doesn’t respond crisply to a control input and the motion feels spongy or delayed. The pressure doesn't rise as quickly and consistently, which can also cause fluctuations under changing loads. In addition, when pressure fluctuates, those air pockets can lead to cavitation-like conditions where pockets form and collapse, causing noise, vibration, and potential damage to pumps and valves. To fix this, purge the air from the system and improve filtration. Bleed air from lines and the reservoir, prime pumps, and check seals and fittings to prevent air ingress. Use proper filtration and deaeration to remove dissolved or entrained air and prevent it from returning, and ensure the reservoir is vented and filled correctly so the fluid remains in a largely air-free state.

Air in hydraulic fluid makes the system more compressible, which disrupts the normally firm, immediate transmission of force through the fluid. Those air bubbles act like tiny cushions, so the actuator doesn’t respond crisply to a control input and the motion feels spongy or delayed. The pressure doesn't rise as quickly and consistently, which can also cause fluctuations under changing loads.

In addition, when pressure fluctuates, those air pockets can lead to cavitation-like conditions where pockets form and collapse, causing noise, vibration, and potential damage to pumps and valves.

To fix this, purge the air from the system and improve filtration. Bleed air from lines and the reservoir, prime pumps, and check seals and fittings to prevent air ingress. Use proper filtration and deaeration to remove dissolved or entrained air and prevent it from returning, and ensure the reservoir is vented and filled correctly so the fluid remains in a largely air-free state.