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I see Teflon tape on the npts.
If I was you I’d at least closely scrutinize every single element of that fuel system. I’d prob take the entire fuel system out and start from scratch.
That’s such an egregious no no I would never be comfortable without double checking everything.
I see you mentioned that this plane has had several recent pre-buys.
They need to be called out.

Based on what you found are you going to pull the other tank?

A couple of thoughts for you….

1) Good on you for taking on the tasks and upping the “education” part of the E-AB rules! A lot of folks that buy airplanes just take them to mechanics and never develop any of the techniques or knowledge of builders.
2) Clean off the old Pro-Seal. Yeah, you can goop, and goop, and goop….but eventually you’ll get poor adhesion tat can lead to leaks. Do it right, do it once. Try “Poly-Gone” solvent.
3) That “loop” of line you made is a good practice part, but there are some pretty deep gouges from your tool that make it sketchy to actually use. If you are goign to go that route (which is a good design solution), re-make it until you get one that doesn’t; have gouges. Wrap/pad the offending part of your tube bender with some gorilla tape. Fortunately, a roll of tubing is cheap - I make a LOT of scrap parts, and have been doing it all my life…..
4) I wouldn;t worry too much about chips in that “air gap” - they won’t go anywhere, can’t interfere with anything, and compromise anything.
5) As mentioned above, the teflon tape is troubling - since you’re already essentially rebuilding the fuel system, I’d check every fitting from the tank to the cylinders to make sure the system is clean and sealed with somethign that cant cause debris.

Paul

Richard Connell said:

If I was you I’d at least closely scrutinize every single element of that fuel system. I’d prob take the entire fuel system out and start from scratch.

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+1
Also note the fuel line wear mark on the landing gear weldment. At some point it will fail.

I have not seen that many 90 degree fittings in a fuel system since I worked and RV-8 that had vapor lock. Do what you can to eliminate as many as possible.

Carl

Other comments withstanding;
#5. The anti-rotation bracket is fine and is per early instructions before Vans did the prefab part.

SquawkVFR said:

Forgive my ignorance, but what's wrong with Teflon tape on fuel fittings?

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There is a VERY good chance that bits of teflon tape can get into the fuel system and stop it up.

Yes, applied properly it should not happen, but it DOES, and often. It HAS caused deaths!

SquawkVFR said:

Thanks, Paul.

Sounds like I've got lots of work to do.

Any suggestions about getting the bend around behind the landing gear mount? I can't see how to do it any other way than by hand and hoping the tube doesn't collapse in the process.

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Honestly? While I am a big believer that any line which isn’t subjected to flexing (crossing an airframe/engine interface) should be a solid line because they last the same amount of time as the airframe (that is, they are permanent), I have heard nothing but awful language from folks trying to install the lines around gear legs on tricycle gear RV’s….and will allow that flex lines DO have their place sometimes. Yes, you can continue to learn and make a good line for that spot - or call Tom Swearengen at TS Flightlines for a flex line. I’d probably beat my head against the first option for a few tries (and some scrap), but might end up with one of Tom’s lines…..

For calibration, on my Rocket project, I had three lines to make between the filter, pump, and firewall, and managed to each of them on the third try… and I’ve been doing this for fifty years. I DO like the way they finally turned out though!

Re. the fuel line and the gear leg tower, there probably isn't a good answer for how to get a new tube routed behind as per the plans, at this stage of the build. I've seen other examples of the fuel line routed in front of the gear leg bracket and provided there is not metal-metal contact it shouldn't be a big issue.

If the hard line is completely replaced with a flex line as some have suggested then there will be some new issues to resolve;- the larger diameter flex line will come pre-terminated with B-nuts and those nuts and line will not fit through the grommets in the brackets on the fwd face of the spar carry through.

Another possible solution is to make a break in the line somewhere around the gear leg tower and then use a straight AN815 union to join the two segments of line. The outer segment may be flexible or aluminum and the other tubing between the gear leg and the fuel selector will remain as-is, apart from getting flared on the end for the union. The bracket that supports the brake line and wiring and fuel can probably be unscrewed and slid sideways to facilitate access. The best location to break the line would be determined by the ability to get a flaring tool into position.

Good luck I am sure you will find a solution.

First things first........shop vac.......

SquawkVFR said:

This plane is ten years old and has 200 hours on it. You think the risk still exists?

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Yes.

SquawkVFR said:

What happens when the teflon stops up the fuel system? Does the engine just quit, or does something else happen?

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Complete loss of power from blockage of the fuel system is definitely on the table.

Nor is that all. Because the Teflon reduces friction, it’s easy to over torque the fitting (causing cracks) and/or the fitting can loosen if it’s subjected to lots of vibration.

Teflon on fuel fittings is a major no-no and indicates there was at least one massive hole in the builder’s knowledge bank.

...adding to Sam's comment (shop vac), put a critical eye on those wire bundles where they rub up against a hard line. Either separate them with "enough" distance, or put some kind of UHMW lo-friction bearing material between them, etc... I just saw a nice RV-14 up for auction due to fire (written off); the fire started in the central tunnel/fuel selector/boost pump area.

Lastly, buy a set of lines from Tom (TS/AS Flightlines) -- he's got them ready to go...

Consider TS Flightlines. Tom can fab flex fuel line exactly the right length. No need to bend tubing.

Please listen to all the good advice and observations here. All good advice from builders who have been there. The school of hard knocks I like to call it.
This is obviously a repeat of the many messages here.

Stop trying to roll your own rigid fuel lines and get flexible lines. Even without the wings on it will take you three to I do not know how many tris to get it right. Then also - rolling your own means you now have to buy the correct tube bender and flaring tool as well.

Get rid of all the teflon as well as the 90 degree fittings. It has killed a number of people thinking it is ok.

I am halfway around the earth but feel like buying a ticket to get over to in order to help you get on track. Is there not a builder close to you or an EAA chapter where you can get help? We all have to start somewhere and I really feel that you should start with the basics. I am attaching the Section 5 document from Vans. It will be a good start. OK you are not building but --- Read it from start to finish.

I hope this helps.

I feel for you mate. It’s an unfortunate place to find yourself and a poor indictment on the hobby and industry as a whole.
I labored over my first RV. Was very sad when I sold it, but endeavored to keep good relations with its new owner and have helped him many times over the past 6 years with minor maintenance related queries. When he sells it to its third owner I’ll still answer the phone.

The whole concept of “you bought it, your problem”, for a homebuilt is an anathema to me.
Sadly though, sheer demographics and the passing of time, plus the probable peak in RV completions being close or soon to be behind us -means that eventually everyone will be owning a plane they didn’t build.

The one and only helpdesk for most of those non builder owners will be VAF.
It’s a great resource and we should all support it.

One last thing…. You will get through all of these issues relatively quickly. Then you’re going to have a blast and will forget these speed bumps. So keep at it.

SquawkVFR said:

Thanks for that explanation. I inspected all fuel lines forward and aft of the firewall and found that the only place Teflon tape has been applied is at the fuel selector. Fortunately, the first component downstream of the fuel selector is the fuel filter, which has a much larger surface area than any stray segment of Teflon tape. I think for now what I'll do is leave the Teflon in-place, so I don't further contaminate the fuel system by the process of extracting the Teflon taped fittings. I'll pull the fuel filter and inspect it (clean it if necessary) then re-install the fuel filter and keep rolling. Do you think there's any risk in proceeding with this plan?

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Glad it isn’t an airplane-wide problem! I confess I am not qualified to comment on the proper fix. My assumption is that the teflon has to come out, but I have to let someone wiser tackle the whether & how.

Lots of good advice here already. The fuel system is obviously important to be 100%, too many (RV) stories that have ended sadly. Too many real examples in this forum to ignore.

Working with tubing is a developed, and perishable, skill. Building is an exercise in patience and approaching each problem as a puzzle. Make a tubing straightener to get the most from your "tries". 3 tries is a minimum. Although I see myself a great tubing bender, I struggled recently with a little tubing project, stepped back and hit it an again until it worked perfectly. Follow Pauls comments carefully, tubing is, indeed cheap. This is redundant to what is already addressed. . . .but . . there is more.

Debris is easily generated when building/assembling tubing - - I like to take some cheap ear plugs and blow then though the tubes and hoses to ensure they are clean. Always use fresh foam and cut it down to fit in 1/4" tubes. Just blow it through with compressed air. Use 3003 tubing as it bends nicely, and is proven to work quite well on the RVs.

All of these issues can be solved and you are learning a ton through the process. It will make you better. You’re getting to know your machine, and how to identify maintenance items down the road.
Education is expensive and time consuming. Keep a positive attitude and before you know it, you will be enjoying your time flying a better, safer, airplane.

You didn't get screwed -- you got provided with an opportunity to learn more about the airplane you'll be enjoying for many many years to come. How many Cirrus/Bonanza/Cessna drivers actually know where their fuel lines are??

OTOH Van's engineering/design was a little off when considering builder skill when they designed some of these subsystems -- not all of us are Tony Kirk, Scott McDaniels, Jay Pratt, etc. etc. The fuel system routing is arguably one of the most fraught areas in the RV series. It didn't get fixed until the -14, and even then they picked the wrong Andair valve...oh well...

SquawkVFR said:

That's a neat little trick with the earplugs. Thanks for sharing it. Would you mind pointing me to the examples you referenced about RV stories that ended sadly due to fuel system issues? I love learning from the mistakes of others whenever possible.

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Here is one sad and notorious example with two fatalities that was caused by the builder who used the incorrect sealant in the fuel system:

SquawkVFR said:

The concern expressed in this thread so far has been the use of Teflon tape. This report indicates that the builder used RTV to seal fuel lines. Although this report is informative, the build plans I have do not state that the use of RTV is appropriate for sealing fuel lines. Section 8 of the Construction Manual says to "Use Fuel Lube (a sealing paste available in supply catalogs) when installing AN fittings with pipe threads. Do not use Teflon tape!" A search of Aircraft Spruce for the term "fuel lube" yielded the following product: https://www.aircraftspruce.com/catalog/cspages/ezturnlube.php?clickkey=9406 which is not RTV or Teflon tape.

Although I feel for the loss of this family, a cursory review of this information reveals that the builder deviated from the build plans and that this lawsuit is therefore frivolous. Yes, the loss of life is tragic, but the builder bears full responsibility here, IMO.

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Unfortunately the builder deviated from the plans and did not follow good practice when sealing NPT fittings i.e. Loctite 565 or 567 paste (or fuel lube per Van's construction manual section 5). RTV and teflon tape can both cause blockages and in another recent example of a forced landing that was reported on VAF a loose particle of fuel tank sealant blocked the fuel flow sensor because it had been installed in the incorrect location, by the builder, against the recommendations of the manufacturer. These are just a couple of examples and there are certainly many more!