What brand is the vacuum oil changer?
Most venturi vacuum generators are most efficient at 70 psi. Overpressuring the venturi will lead to long vacuum times and decreased vacuum levels.
My company builds vacuum oil changers, mainly for on site maintenance, so feel free to ask any questions you have.
I recommend replacing your drainplug with a quick connect fitting instead of going through the dip stick tube. The dip stick probes are so small in diameter that it takes FOREVER to evacuate oil this way. Again, please ask any question you like and I will answer to the best of my ability.
