Which of the following is a daily air compressor check?

• A. Oil level
• B. Hydraulic fluid level
• C. Tank water level
• D. Fuel level

Answer: (A)

Regular lubrication is essential for an oil-lubricated air compressor. Checking the oil level each day helps ensure there’s enough lubricant to coat bearings and moving parts, reducing friction, controlling heat, and preventing wear or damage. If oil is low, components can overheat and fail, shortening the unit’s life. The other items aren’t a standard daily check for most air compressors: hydraulic fluid is for hydraulic systems, not the compressor; draining condensate from the tank is important but is about moisture removal rather than monitoring a water level; and fuel level is only relevant for engine-powered units and isn’t a universal daily check.