Leak in fuel vent line

[LeonardWestermeyer]

I have been noticing a definite fuel odor in the cockpit of my 7A. Also noticed a blue stain where the vent line exits the cabin for the wing.

Thought it might be the flare compression nut loose, but tightening it did no good. About to replace the entire line, but decided to remove the AN833-4D pass-through elbow and to my amazement found this:

The hole was big enough to see it looking through the interior of the fitting!

Has anyone else had this happen to them?

It would be good to check your fittings for defects before installation!

 

[PaulvS]

Is it a genuine AN fitting with the stamp on the side? The hole is possibly a casting defect during manufacturing. I usually check most hardware before installation, just in case there is a defect.

 

[LeonardWestermeyer]

Actually it doesn’t have a stamp on the side. I received the part from Vans in the Kit.

Go figure!

 

[TS Flightlines]

That is interesting. Obviously not AN spec, and since its experimental it doesnt have to be. The kit manufacturer can certify their kit with whatever they want. Like plastic lines, rubber hoses, hose clamps, barbed fittings, etc.
The AN material spec was 2024T3 (now 7075T73). There are ALOT of "AN fittings" out there that look like, smell like, have the basic dimensions, but not the proper material for a true AN spec fitting. In order for it to have the "AN" stamp, it must have passed all the specs required under the MilSpec. That process is a major headache.

The adapters we make meet all the specs for dimensions, color, material, but are NOT stamped 'AN", because they are NOT certified, even though we manufacture them to Mil Spec. So why are they not 'certified"? Its a long process by the FAA certification branch to have independent labs qualify the fittings for materials, dimensional specs, correct color, pressure test qualifications, etc. Its also an expensive process, and most recoup some of that expense by what seems to be a high price for the fitting. And, the backlog now to try and do the certification process is, well, frustrating. Steve and I put that process on the back burner for a while after a 3 year wait. Granted, part of that was during Covid--but we were doing our adapters and hose ends at the same time.

So, the best suggestion I can give is to either use a true 'AN' stamped fitting; or if you dont, use one that qualifies but isnt certified. ASK the manufacturer for the spec data on their fittings. Lots of luck if you ask Summit, Jegs, or other 'race car parts'. They probably dont know, and if they do, its probably would be 6061T6. If they tell you its 2024T3 or 7075T73, its 'most likely' a correct fitting.

Tom