I made one for my truck. Got a 1/4 npt by barb adapter (brass). Took a plastic tubing brass insert collet (the one you install in the end of plastic tubing to keep it from collapsing) and pinched closed the top end. Then the open end of the collet went over the barbed end which allowed it to move up and down over the barb but not come off. Venting could then take place without anything getting into the axle.


Country Roads, West (By God) Virginia
http://community.webshots.com/user/geezer