rebuilding a vacuum pump and need help

[collinsj57@adelphia.net]

I am rebuilding a used vacuum pump and need a little help. When looking at the hub the slots for the vanes have a slight angle to them meaning the outside of the vane where it touches the pump wall will ether be leading ( angled into the direction of travel ) or lagging (angled into the direction of travel ) . being the pump had been opened prior to my getting it I am not sure it was reassembled correctly. I suspect the vanes should be leading or pushing forward into pump wall and direction of travel as I believe if the vane lag they can bind up and break.

Can anyone tell me if my thinking is correct or do I have it all backwards.

Thanks

[szicree]

I'm sorry I have no clue about the vane direction, but don't they make manuals for this kind of thing?? Do you really want to take Joe Blow's word with regard to someting that can make such a mess of your instruments if it goes ka-blooey?

Steve Zicree
RV4 Fiberglass

[sf3543]

Here's some information you may be interested in from the AVWEB site: http://www.avweb.com/news/maint/182905-1.html

"The hub slots of Airborne pumps are canted in the direction of rotation. For this reason, Airborne offers different pump models for clockwise and counterclockwise applications. The most common model numbers are 211CC and 441CC (for counterclockwise rotation) and 212CW and 442CW (for clockwise rotation). It's not difficult to break the code.
Installing a wrong-direction pump is a sure prescription for premature failure. Most Continental engines require a clockwise pump, and most Lycomings require a counterclockwise pump. But not always. "