Drilling into the effect of air bubbles in hydraulic equipment


You might not expect that something as benign as air bubbles in oil could have such an impact. Aeration can cause premature wear, machines to underperform and hydraulic component failure.

What you may notice… 

  • Unusually noisy hydraulic equipment

  • ‘Spongy’ equipment response

  • Frequent oil changes required due to increased wear particles

  • Components are failing unexpectedly and leading to downtime

  • False readings from diagnostic sensors

Why it may be aeration…

  • Noise: You could have enough air bubbles in the oil for the pump to make significant noise trying to discharge the aerated oil. Depending on the design of your equipment, previously dissolved air may be precipitating as bubbles before the inlet of the pump.

  • Machines Underperforming: Aeration will cause oxidation and sludge. This ultimately reduces the amount of force transmitted by the fluid.

  • Frequent Oil Changes: The purpose of lubricating oil is typically to create a thin liquid barrier between interacting metal components. Enough air opens up the opportunity for contact, creating wear particles in the oil.

  • Components Failing: Aeration can cause components to fail quickly. If a rotating component relies on oil for consistent lubrication, small amounts of air can inflict significant damage. Systems using oil for cooling may experience localized hotspots.

  • Diagnostic Sensors: Aeration can interfere with sensor readings, causing inaccurate measurements.


Why it will only get worse…

Modern hydraulic equipment is trending in a direction that highly influences oil aeration. Manufacturers are moving to smaller reservoirs, longer oil service intervals and lower viscosities to improve efficiency. All these factors negatively impact a hydraulic system’s ability to resist oil aeration.

Measure aeration with ATA Aerify™

Aerify™ Measure provides a continuous, real-time measurement of oil aeration rates in engine or drivetrain dynamometers, in-vehicle or test bench applications.

  • Aerify™ Sensor

    • A turn-key system to accurately and repeatably measure oil aeration, in real-time.

  • Aerify™ Service

    • On-site aeration test service. ATA engineers install and measure the aeration levels in your hydraulic application.