This works great for all my vehicles. and only uses three parts
Use a quick connect air hose adapter like the one referenced in the link in the above post.
buy a pipe thread cap that fits the q/d adapter threads. (got mine at home depot). drill a whole in it for a vent. you will use this cap as a nut to secure the q/d adapter
buy another reservoir cap (dealer/junkyard/wherever)
Drill a hole in the top of the resorvoir cap (make it a tight fit) and insert the q/d adapter. lock it down with the drilled cap.
Done!
if you did not drill the hole in the reservoir cap the correct size or you find it leaks air a bit, you can apply some sealant inside the cap around the nipple or fabricate a gasket out of some rubber.
