It's amazing how the vacuum pump manufacturers talk about how critical it is to use the proper high vacuum pump oil and then provide no technical information whatsoever on what the characteristic of that oil should be. This goes for U.S. General (Harbor Freight), Robinair, and MasterCool. I've never seen the likes of it.
Some have said to dump the oil after a month, since it's hygroscopic. Sounds like they are putting this oil in the same league as PAG oil. Any thoughts, Paul?