Eliminate the Vac pump gear on engine?

Slagergren · #1 06-10-2010, 05:37 PM

I have an O-360-A1D and no longer need for the vacuum pump and would like to remove the associated mount & gear from the accessory case. My question is, what harm if any is there in operating the engine w/o this vac pump mount and its free-wheeling gear?

Thanks, Steve

tommylewis · #2 06-10-2010, 06:00 PM

The only reason that I would keep it so that in case I later wanted to added a backup alternater to that vacuum pad. I had Aerosport build my IO360 with that as an option in case I ever want to add an backup alternater. I know many others that omitted it.

John Courte · #3 06-10-2010, 06:07 PM

I kept the gear, but pulled the vac pump off and slapped a cover plate on there. You might want that to drive something else someday.

Slagergren · #4 06-10-2010, 06:10 PM

Thanks for the reply, I think unless others give good reason against it, it to makes sense to remove extra weight and spinning mass from the engine until I have a need for them.

Thanks again

mikegraycmg · #5 06-10-2010, 08:45 PM

This has been tried before. My recollection is that the results were not good. Lycoming has functions for the gear other than simply driving the vacuum pump. I think that the gear also has something to do with the oil path through the accessory case. You probably don't want to mess with it.

lancef53 · #6 06-11-2010, 06:26 AM

What is the process for removing the gear to run an inverted pickup? My raven setup pulls from that point when inverted, so I removed the gear to allow the oil to flow easier. Is that the wrong thing to do? Should I remove the complete housing also?

rocketbob · #7 06-11-2010, 09:12 AM

Mike is correct in that there's a galley from the accessory case that feeds the vaccum pump drive. It is in series and before the oil pressure relief valve so you would lose some oil pressure as a result. If you remove it then it would be ok only if you removed the accessory case and plugged the galley.

rocketbob · #8 06-11-2010, 09:23 AM

Now that I think about it, one could easily turn a plug on a lathe that would be a close fit for the vacuum pump shaft, and that would plug the galley.

mahlon_r · #9 06-11-2010, 12:39 PM

It is 100% acceptable to remove the vac pump drive gear and drive housing as an assembly, and then install a cover plate directly on the accessory housing. You can remove the long studs and install shorter ones or fabricate spacers out of 1/4 tubing to make up the distance on the long studs to the nuts and washers you use to hold the cover plate on with, if you decide to leave the long studs.
Good Luck,
Mahlon
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