[QUOTE=NOBLNG]Along the lines of the brake bleeder is my transfer case and differential filler. It is made from a 2qt jar, a metal disc in place of the glass cap with a tube and an airline fitting soldered on. It can be used with a bicycle pump,or very low air pressure from a regulator. Make sure to remove the valve core so it stops when you want it to.
Its the simple ones that make you smile when you use them .
I may have to make myself one of those!