Pre-Flight - Drain Gascolator

[PTK]

1 hour ago, teejayevans said:

Probably a good idea, I've had then leak because of debris stuck in them, but repeated drainings have cleared it. Anyone know exact drain used, they look like flush mounted curtis but don't know thread size?

I think thread is 7/16”- 20 

http://www.chiefaircraft.com/mdi-f391-53s.html

[jlunseth]

On the question why it is a problem from the outside and not the inside, I have not taken one apart to check, but from the inside it is probably a rod with a round rod end of course, and a screw of some kind holding the sealing disc on, and there will of course be an o-ring in there somewhere.  This arrangement automatically creates a symmetrical pull against the spring that wants to reseal it, where the sealing ring stays flat to the rod end or at least the screw.  If you push with the sump cup rod, it is a tiny thing, and you push on one side of the sealing ring but not the other, that produces an assymetric motion guaranteed to cock the ring, which causes it to catch in the open position.  Like I said, I have not bothered to take it apart and see, but that is my guess.  Maybe someone who has disassembled one can explain it better. 

[Oscar Avalle]

I was not able to find a free download, but I did find where you can purchase it as an $8 download. Much more detailed than the 1965 version I have.
https://www.eflightmanuals.com/ITEM_EFM/SDETAIL_EFM.asp?mID=4839

Yes, much more detailed! To add to the discussion, in the POH in the preflight section it states that the first step in the preflight is to sump the tanks for 5 seconds right and then 5 seconds left.


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[xcrmckenna]

My CFI told me of a mooney driver who ran out of fuel and crashed. He took off with plenty of fuel, slumped the tanks, pulled the gascolator and evidently one thing or the other didn't stop leaking and he lost his fuel. Since I heard this the first thing I do is to sump both, pull the gascolator then push the plane back a few feet. Next I do the exterior preflight and before I get in the plane I look at the ground under the plane if something is leakin it is easy to see.

I Ike that idea. I always check my fluids first on preflight. The fuel and oil, then I do my walk around.


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[MBDiagMan]

The first thing I want to do after vacation is find out how to deal with the gascolator on my '63 model.  I haven't found it.  It has no ring on the selector.  I hope I don't have to remove the cowl to deal with it.

[mooniac15u]

19 hours ago, MBDiagMan said:

The first thing I want to do after vacation is find out how to deal with the gascolator on my '63 model.  I haven't found it.  It has no ring on the selector.  I hope I don't have to remove the cowl to deal with it.

On a '63 it should be in the nose gear well.

[MBDiagMan]

Thanks Mooniac!  Now all I have to do is remember to check it before I fly when I get home.  I am enjoying the vacation, but I am REALLY anxious to roll the Mooney out and go fly.  I don't think I will overlook a thorough preflight though.

[Rick Junkin]

I use a GATS jar with a funnel stuck into the neck for catching my gascolator sample. I drain the wing sumps first, and leave that fuel in the GATS jar so that it doesn't blow over with the funnel stuck in it when I set it under the gascolator drain port. The funnel doesn't reach all the way to the bottom of the airplane, but its close enough and a big enough target to catch the fuel. Works like a champ.

Here's the kind of funnel I use, and I have the large size GATS jar.

Cheers,
Rick

Here are some additional photos that show the modification I made to the funnel so that it fits securely in the GATS jar, and of it positioned under my TLS.

Edited June 4, 2017 by Junkman
added photos

[GeneralT001]

Is the gascolator drain directly below the ring in the cockpit on an M20J - so on the belly on the outside of the aircraft?

[Ragsf15e]

40 minutes ago, GeneralT001 said:

Is the gascolator drain directly below the ring in the cockpit on an M20J - so on the belly on the outside of the aircraft?

Yeah, should be belly, below the ring pull, left side of the airplane.  There’s a few drains along the nose and it’s worth getting to know what goes where.  Important for your question, there’s a second drain just forward of the gascolater drain.  The aft one is gascolater, the one ~8 inches forward is the electric fuel pump.

[carusoam]

The pull ring itself is directly connected to the drain in a vertical orientation…. No hoses or pipes to have any bends…

Use Rag’s details to recognize it…

 

In the past… people used to poke the fuel sample cup into the drain hole and activate the drain…

This technique was found too risky for possible damage….. there is a piece of rubber glued to the tip that can get knocked off….

 

-a-

[JoeM]

I was having trouble making full power on takeoff and, after inspecting the finger screen (clean), found the gascolator wasn't draining. When I took it apart, the screen was mostly clear, but the drain hole was plugged. Cleaning the drain and the screen fixed the takeoff power problem. 

+1 for sumping the tanks first, then draining the gascolater. It is the lowest point in the system and should collect water and debris even if the tanks sump clear. It is worth checking to be sure there are no gas leaks before startup.