Which device on a compressor is used to manage lubrication by adding or removing oil?

• A. Oil pump
• B. Sump level gauge
• C. Oil filter
• D. Oil charging port

Answer: (D)

Lubrication in a compressor is all about keeping the right amount of oil in the crankcase to properly lubricate moving parts. The way to change that amount—adding new oil or draining some if there’s too much—is through the oil charging port. This service port gives access to the oil system so you can adjust the oil charge during maintenance.

The oil pump is responsible for circulating the oil and delivering it to bearings, but it doesn’t set how much oil is in the system. The sump level gauge shows whether the oil is at the correct level, but it doesn’t add or remove oil itself. The oil filter removes contaminants from the oil, not adjust its quantity. So the oil charging port is the component used to manage lubrication by adding or removing oil.