psfred

Yes, it is in the procedures. Vacuum pumps are mechanical and they require lubrication after installation in order to prevent galling of the pumps cylinder, piston, & sealing rings. Manufacturers usually supply “Installer Instructions” for a number of reasons, “Reliability” being the most important. This ensures that the replacement item being installed will live up to, or exceed the consumer’s expectations. You would not start a new engine without priming the oil pump/system and since this is a vacuum pump/engine it warrants the same precautions.