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prkaye

Well Known Member
Ok, total newbie question here. I'm trying to figure out the fuel pickup assembly. There's the blue 90-degree angled fitting that goes through the fuel tank access cover (not sure of the part number). This angled fitting is supposed to somehow get coupled to a 3/8" pickup tube via an AN818-6D nut and AN819-6D sleeve. Problem 1 was identifying these parts. Vans throws a bunch of different parts in the brown paper bags, so I sorted them out and picked the ones that looked to be the right size/shape. The sleeve has a 3/8" diameter on one side, and a smaller diameter on the other side. I picked-out the only nut that will thread onto that blue angled fitting. My next problem is i haven't quite figured out how these pieces all go together. The best theory I can come up with is that I'm supposed to push the 3/8" tube through the large-diameter side of the sleeve, and some how ram it through so it comes out the small-diameter side, and then push the sleeve all the way up to the top of the tube (where it is to be coupled to the fitting). Then the nut goes over top of the sleeve. Is this correct?? I can't imagine it being very easy to pull the tube through this smaller diameter of the sleeve... is there a special tool or technique for this? Should I use any kind of lubricant, teflon tape, or anything?
 
Experiment and test fit

Phil,

No worries, it'll be old hat after a while.

The sleeve should have two different outside diameters, but the inside should be all 3/8". There's a female flare on the larger end, that mates to the back end of the flare you'll make in the tube.

This procedure will work with all tubing, whether or not you can get to an open other end. It's a good habit to do it this way 'cuz if you don't and you can't get to the other end, you'll be angry that you flared before putting needed parts:

1. Put the Nut on the tubing, threads up.
2. Put the sleeve on the tubing, smaller outside diameter down, large outside diameter up.
3. Flare the tubing, 37 degrees w/an aircraft flaring tool. Don't use a 45 degree auto tool (this is by far the most often seen warning in RV world - you'll get tired of reading it).
4. Your flare mates to the nipple on the fitting, the sleeve backs up your flare, and the nut engages the sleeve and threads onto the nipple.
5. Don't use any lube/seal/grease/etc.
6. Torque per the Standard Aircraft Handbook.

Practice! You have enough tubing to try a couple before you "commit".

George
 
Great writeup by George. I trashed mine. I would only add the following??..

The ACS (Aircraft Spruce & Specialty Co.) catalog has under AN fittings, a complete image, part number and fitting sizes of all the AN fittings you will ever need. Since the catalog is free, you may want to use it as a reference. It includes examples of almost all the hardware and most other components you will be using on your aircraft. There are many other reference publications as well including many currently sold by EAA National.

Good luck and happy building
 
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