How often should the oil in a vacuum pump be changed?

How often should the oil in a vacuum pump be changed?

• A. Every six months
• B. After each use
• C. Monthly
• D. Weekly

Answer: (B)

The key idea is keeping the vacuum pump oil clean and free of contaminants. When you evacuate a system, the oil can pick up moisture from the air and trace refrigerant vapors. Moisture in the oil degrades the pump’s ability to reach a deep vacuum and can cause corrosion or acid formation inside the pump and the system. Because contaminants accumulate with use, you should change the oil after each use so you start the next job with fresh, clean oil. If you wait longer, those contaminants build up and the pump won’t perform as well. Changing less often—weekly, monthly, or every six months—doesn’t remove contaminants promptly enough to maintain proper pump performance.

The key idea is keeping the vacuum pump oil clean and free of contaminants. When you evacuate a system, the oil can pick up moisture from the air and trace refrigerant vapors. Moisture in the oil degrades the pump’s ability to reach a deep vacuum and can cause corrosion or acid formation inside the pump and the system. Because contaminants accumulate with use, you should change the oil after each use so you start the next job with fresh, clean oil. If you wait longer, those contaminants build up and the pump won’t perform as well. Changing less often—weekly, monthly, or every six months—doesn’t remove contaminants promptly enough to maintain proper pump performance.