A pneumatic oil extractor is a device that uses air pressure to force oil out of an engine. The extractor has a chamber that the engine's oil pan fits into. The chamber has an inlet and outlet for the air compressor hose, and a valve to release the pressure when the extraction is complete.
To use the extractor, the engine's oil must be at a warm temperature so that it flows easily. The extractor is placed over the engine's oil drain plug and the inlet hose is connected to the air compressor. The outlet hose is placed into an empty container. The valve on the extractor is opened and air pressure builds up in the chamber, forcing the oil out through the drain plug hole and into the container. When all of the oil has been extracted, the valve is closed and released, allowing any remainingair pressure to escape.