OK, like I say I've never done that , however in the piston type rebuild pictorial it says to build a jig. And mount the pump on it. Well here, take a look at the link. See if there is anything there that might help you.



http://web.archive.org/web/20050306142927/business.baylor.edu/Richard_Easley/autofaqs/Vacuum+Pump/Rebuild_vac_pump.htm

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Sonny


86 190D N/A 2.5L Auto 265k "Ruby" -Sold-
79 300D 242k "Condi" my first -sold- RIP
2013 chevy sonic hatchback - had to for work