I'm going to buy a rotary pump

[CalG]

Technology is the answer!


What was the question?.....

 

[Raul-02]

I've never used a shop vac to pull a vacuum on a gearbox because,

You can reduce both the CFM flow and the inches of mercury of a vacuum hose by using a little piece of tubing with a hole in it on the vac hose.
About those seals ,,,,,,, Aren't they all O rings? No amount of vacuum can dislodge them. You can't get more than 15 PSI of differential pressure.