vacuum pump m20k

[DonMuncy]

I am seriously considering getting and carrying a spare vacuum pump.

The Mooney parts manual lists a half dozen, including Sigma Tek and Airborne, under various part numbers.

Aircraft Spruce lists Rapco and Sigma Tek with various part numbers.

They carry price tags from about $395 to $700+.

How does one  decide which one to use, and the various values.

[Ethan]

I just took my vacuum system out of my airplane including an electric backup pump. I have them in a box in my hangar. 12volt system. Worked when removed but I don't need them anymore because I have two G5s. Let me know if you want em.

[N201MKTurbo]

How about gyros? My Cessna project has two ancient AN gyros the giant boat anchor kind. They are kind of messed up, I can't even pull the heading knob on the DG. I think I have the DG I removed when I put in my G5 HSI. I would be interested in a great deal on a vacuum attitude indicator that worked.

[N201MKTurbo]

22 hours ago, DonMuncy said:

I am seriously considering getting and carrying a spare vacuum pump.

The Mooney parts manual lists a half dozen, including Sigma Tek and Airborne, under various part numbers.

Aircraft Spruce lists Rapco and Sigma Tek with various part numbers.

They carry price tags from about $395 to $700+.

How does one  decide which one to use, and the various values.

I have had good luck with both. I like the one with the oil seal, I forget which one that is.

[shawnd]

On 11/7/2021 at 1:20 PM, DonMuncy said:

I am seriously considering getting and carrying a spare vacuum pump.

The Mooney parts manual lists a half dozen, including Sigma Tek and Airborne, under various part numbers.

Aircraft Spruce lists Rapco and Sigma Tek with various part numbers.

They carry price tags from about $395 to $700+.

How does one  decide which one to use, and the various values.

That's a darn good question. I ran through this same decision matrix last year. At the end of the day, familiarity with the brand, its reputation for support and product quality from previous experiences got me to go with Tempest. I also use their finewire spark plugs and oil filters. Aircraft Spruce carries these as well:

https://www.aircraftspruce.com/categories/avionics_instruments/av/menus/in/vacuum_ztempest.html

I wouldn't buy an overhauled one unless it really is your spare and you will be swapping it out once your main unit is replaced. For application guide, see

https://tempestplus.com/product/dry-air-pumps/

Good luck!

[DonMuncy]

5 hours ago, Ethan said:

I just took my vacuum system out of my airplane including an electric backup pump. I have them in a box in my hangar. 12volt system. Worked when removed but I don't need them anymore because I have two G5s. Let me know if you want em.

I think that would work fine. Let me know cost if you still have them.

[shawnd]

Be careful to install the right type of pump. The pump can rotate counter clockwise or clockwise.

[DonMuncy]

3 hours ago, shawnd said:

Be careful to install the right type of pump. The pump can rotate counter clockwise or clockwise.

Thanks, did Mooney use both clockwise and counterclockwise? Looks like I am going to have to do some serious research to figure it all out.

[philip_g]

Does anyone make a wet pump for the k? I always wanted to try one

[shawnd]

12 minutes ago, DonMuncy said:

Thanks, did Mooney use both clockwise and counterclockwise? Looks like I am going to have to do some serious research to figure it all out.

It's best to see what you actually have and what is working on the airplane and get that specific type: clockwise or counter-clockwise. The IPC may be a bit confusing in this particular topic. Tempest in my case suggested counter-clockwise. IPC has Airborne clockwise but the one installed in my aircraft was Airborne CC. My $0.02, not an A&P but suggesting logic here :-)  Good luck!

[DonMuncy]

Aha. I suppose the cc in the number indicates counterclockwise. At least something to start on.

[shawnd]

Yep, for example: AA3215CC is the counter clockwise version, AA3216CW is the clockwise version (these are Tempest pumps). Airborne Research pumps have a similar scheme.  SIGMA-TEK ones don't easily tell the story. You can always call up Lasar and get help once you know the model you have installed.

[Guest]

Generally speaking Lycoming engines use a CC pump, while Continental engines use CW pumps.  Continental engines with the pump on the starter adapter are the exception.  The application guide should verify the model you need.

Clarence

[hubcap]

My vacuum failed enroute to KOUN about 2 months ago. I took the opportunity to get rid of it altogether….along with the backup altimeter, airspeed indicator, and the artificial horizon replacing them with a G5. 

Edited November 9, 2021 by hubcap

[PeteMc]

What would you buy if you started up your plane today and had no VP?  I would buy that.  Odds are you're not going to have this spare vac. pump put in and then taken back out in a few days when you get back to your home (or mechanics) airport.  You're going to have it swapped and be done with it.

The other equally important question is how do you store it!!  My guess is that it's going to have to be in a fairly big box with a lot of padding.  I think there is some protection for hard landings when the VP is fully spinning.  But how much shock can they take when sitting in a box?  I've whacked my head pretty hard in turbulence before, so I could see a non-padded VP taking a good whack too.  And this last spring while landing in strong winds I had a gust stop gusting while I was just a few feet above the runway and dropped with a good bounce.  Again, I don't know how durable they are in a box, but that was a good jolt. 

[Ethan]

20 hours ago, DonMuncy said:

I think that would work fine. Let me know cost if you still have them.

I will go take photos of the things I have and send them to you. How about $200 for everything.

[DonMuncy]

I will watch for your photos.

[Ethan]

Don, here are my removed items. 

[DonMuncy]

Sounds OK to me. How do you want to get paid.

[RobertGary1]

On 11/9/2021 at 9:09 AM, hubcap said:

My vacuum failed enroute to KOUN about 2 months ago. I took the opportunity to get rid of it altogether….along with the backup altimeter, airspeed indicator, and the artificial horizon replacing them with a G5. 

I would just recommend some diverse backup. A vacuum attitude is the most economic choice. All the major manufacturers have had software issues resulting in dual AHRS failures. This was mine and Garmin has issued an SB for a patch. But as a Silicon Valley software guy I can assure you all software has bugs some just haven’t been found.