Which term refers to the process of removing air from a hydraulic system?

• A. Rotary Switch
• B. Hydraulic Circuit
• C. Hydraulics
• D. Hydraulic Bleed

Answer: (D)

The concept here is removing trapped air from a hydraulic system, which is done by bleeding the system. Air in the fluid makes the system feel soft and responsive poorly because air compresses, unlike the hydraulic fluid, so you don’t get clean, predictable motion. The process of hydraulic bleeding involves opening a bleed valve and forcing fluid through the line so air can escape, usually while keeping the reservoir topped up. Once bubbles stop, you close the valve and repeat as needed until the system responds firmly and consistently. The other terms describe parts or fields of hydraulics (a control for electronics, the path the fluid takes, or the overall subject area) and do not denote the act of removing air.