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Cleaning up Vacuum Pump Removal


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During our last annual, I went ahead and had the mechanic remove the vacuum system and cap the mounting location as our instruments are all solid state now. I was a little stumped to find this... I’ve been trying to do some research on my own, but would appreciate other’s input. Can I not just have him replace the intake manifold pipe coupler, and get rid of this whole tubing assembly/valve/and vacuum regulator as well? Tried to peer under the dash, and believe that the vacuum filer is connected to the large tubing going through the fire-wall. Thanks!

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I had mine done during annual, but I was very specific.  The mechanic removed everything vacuum related from the engine to the firewall.  The avionics techs (different shop) were responsible to remove everything behind the panel.  So yes, it can all be removed, but from the firewall to the panel it’s probably zip tied and secured in many places and it’s gonna be a pia.  Or maybe not.

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I can't play the video.

When I redid the panel and removed the vacuum pump I removed everything on both sides of the firewall. No vacuum pump, no vacuum system, no reason to leave anything behind that is only related to the vacuum system. 

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Charles,

Expect that is a precise flight alternative for a back-up vac pump... it uses the vac generated by the intake system...

Get that uninstalled before it hurts somebody... :)

That thing was good for about a year... where people noticed it has a lot of limitations....

 

There is a lot written about them around here... including how to use it...

The follow up is a vac pump mounted in the tail...

The modern version is a back-up alternator mounted where your primary vac pump just vacated...

Have your mechanic verify what needs to get removed...

PP thoughts only, not a mechanic...

Best regards,

-a-

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Time for a more thorough and educated maintainer.  He’s left the old Precise Flight SVS system in place, plus the vacuum regulator at the firewall, likely left the central gyro filter in the panel as well, but that’s just a guess.

Clarence

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The SVS is really easy to remove. A piece of cake on the engine side. If you removed the whole vacuum system , you only need to cap the firewall and the hole in the intake side. 
the SVS cable inside behind the firewall is a little more involved

the vacuum system behind the firewall is a lot more involved to be done right 

i understand the shop reluctance. It sounds easy from an owner standpoint to just remove 1 item. But very often, it involves taking out seats, avionics stacks , .... to have access 

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On 2/28/2021 at 3:34 PM, M20Doc said:

Time for a more thorough and educated maintainer.  He’s left the old Precise Flight SVS system in place, plus the vacuum regulator at the firewall, likely left the central gyro filter in the panel as well, but that’s just a guess.

Clarence

Here's what my A&P friends tell me: Mooney's are not the easiest plane to work on and sometimes work takes a little longer than on a Cessna or Piper especially if you have to get behind the instrument panel on a later model. And, Mooney owners have a reputation for ...how do I say this politely ... being, er, frugal. So, unless the owner specifies that they want all the stuff removed, a lot of shops won't to avoid arguing over the cost of the labor when the owner gets the bill.

I think the reasonable thing to do is discuss the options with the owner. In my case I had the ADF removed in three stages: The panel mount unit was removed during installation of other avionics. The antenna was removed and the hole plugged and painted during other work at a different shop. I removed the wiring between the panel and antenna when I refurbished the interior and had it inspected and the W&B updated. So three operations to get it all removed and three W&B updates, but it was the most efficient way to do it.

Skip

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While Mooney instrument panels are a challenge to work on, I doubt that many owners say leave half the old system and old wiring behind.  Orphaned systems and wiring make an already crammed panel even worse.

Clarence

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When I had my avionics upgraded, I told my shop to remove all the vacuum related stuff firewall aft.  They removed the peanut gauge, wired the vacuum light such that it illuminates when you hit the push to test but it otherwise doesn't illuminate (I may need a placard for this or cover it at some point).  And as far as I can tell they removed removed all the vacuum tubes under the panel.

However, they left in the vacuum regulator (the one with the garter filter) and another vacuum filter that I'm not sure was even plumbed to anything before the mod.  I had to then remove these two items that were bolted to the cockpit side of the firewall.  I believe they didn't want to touch these as they would create a hole in the firewall once removed.  This and everything firewall forward me and my IA handled.

Of note:  my engine cover installation for my IO-360-A3B6 looks a little bit different.  It turns out that you have to keep the vacuum pump adapter (and consequently the drive gear) for it to seal right.  I was hoping to save the extra couple of pounds.

Bruce

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15 hours ago, MisfitSELF said:

When I had my avionics upgraded, I told my shop to remove all the vacuum related stuff firewall aft.  They removed the peanut gauge, wired the vacuum light such that it illuminates when you hit the push to test but it otherwise doesn't illuminate (I may need a placard for this or cover it at some point).  And as far as I can tell they removed removed all the vacuum tubes under the panel.

However, they left in the vacuum regulator (the one with the garter filter) and another vacuum filter that I'm not sure was even plumbed to anything before the mod.  I had to then remove these two items that were bolted to the cockpit side of the firewall.  I believe they didn't want to touch these as they would create a hole in the firewall once removed.  This and everything firewall forward me and my IA handled.

Of note:  my engine cover installation for my IO-360-A3B6 looks a little bit different.  It turns out that you have to keep the vacuum pump adapter (and consequently the drive gear) for it to seal right.  I was hoping to save the extra couple of pounds.

Bruce

When Lycoming ships an engine for an airframe which doesn’t have a vacuum system, they leave the gear and housing off.  The cover plate goes on, then four long bushings over the studs, then lock washers and nuts.  So you can remove the drive gear.  
Some airframes use the vacuum pump pad to drive an backup alternator made by B and C.

Clarence

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