Air passage insert for oil fill spout

In an air compressor having an oil crankcase with an oil fill spout disposed on a side of such oil crankcase, the improvement comprising an air passage insert comprising:

• (a) an air communication means having a first end thereof disposed within an interior portion of said oil crankcase at a position above an oil full level and a second end thereof being in communication with the atmosphere outside of the crankcase for communicating air from the interior portion of said oil crankcase in a space located above such oil full level to the outside atmosphere;
• and
• (b) an attachment means engageable with both said air communication means and said oil fill spout for attaching said air communication means at least to one of said oil fill spout and the interior portion of said oil crankcase thereby enabling air to be vented to the outside atmosphere from the space located above such oil fill level during an oil filling process.