Removing fuel tank from assembled RV-10

[mikelupo]

Hi,
My RV-10 is a flying bird. But I've developed a fuel leak in the inboard corner up against the spar... basically in a spot that I will need to remove the tank to repair.
I am looking for advice on removing/reinstalling the tank.

In order to get the tank off the plane, I need to get access to the 21 through-spar AN-3 bolts. I think I am going to need to remove the Aileron torque tube that runs along the aft side of the main spar to make the job easier. This, of course, means removing the wing-tip so that the torque tube can exit the wing through the lightening holes.
Has any one in this forum accomplished the removal/reassembly of a fuel tank? I plan to use teflon sockets so that I don't scratch the spar.

Background...
My plan is to remove the tank, repair the leak and reinstall. Best case scenario, I may discover that it's only just a rivet leaking and I'll fix just that, but I think it's going to be the seam where the rib, skin, and back of the tank come together at the back corner. Hence, I think I'll have to drill out the rivets on the entire rear T-1002 tank baffle (over 200 rivets), clean and re-proseal and re-rivet the entire thing back in place.

Another impetus for possibly removing the entire back of the tank is that I would like to add a filler neck. This (purchased) plane was built with an inboard and outboard wing tank. Only the outboard tanks have filler necks installed. The outboard tank has hose that feeds inboard tank. I'd like to consider separating the tanks so they can work independently.

 

[KatanaPilot]

Hi,
My RV-10 is a flying bird. But I've developed a fuel leak in the inboard corner up against the spar... basically in a spot that I will need to remove the tank to repair.
I am looking for advice on removing/reinstalling the tank.

In order to get the tank off the plane, I need to get access to the 21 through-spar AN-3 bolts. I think I am going to need to remove the Aileron torque tube that runs along the aft side of the main spar to make the job easier. This, of course, means removing the wing-tip so that the torque tube can exit the wing through the lightening holes.
Has any one in this forum accomplished the removal/reassembly of a fuel tank? I plan to use teflon sockets so that I don't scratch the spar.

Background...
My plan is to remove the tank, repair the leak and reinstall. Best case scenario, I may discover that it's only just a rivet leaking and I'll fix just that, but I think it's going to be the seam where the rib, skin, and back of the tank come together at the back corner. Hence, I think I'll have to drill out the rivets on the entire rear T-1002 tank baffle (over 200 rivets), clean and re-proseal and re-rivet the entire thing back in place.

Another impetus for possibly removing the entire back of the tank is that I would like to add a filler neck. This (purchased) plane was built with an inboard and outboard wing tank. Only the outboard tanks have filler necks installed. The outboard tank has hose that feeds inboard tank. I'd like to consider separating the tanks so they can work independently.

I did this recently to install the Sky Designs ER tanks on our flying RV-10. Yes, removing the aileron torque tube makes the process much quicker. I did not do that one time and regretted it.

If you don't want to go through the hassle of trying to repair and modify your tanks - I do have two fairly new (40 hours) standard capacity, standard build tanks with Newton Aero 300 fuel caps, inboard return fittings (for SDS or EFII) and outboard fuel bungs (had originally planned on HW outboard tanks). $2500 plus crating and shipping, or pick up in the Atlanta area.

 

[ctennis]

I did a video about it: https://www.youtube.com/watch?v=0vHQZuK9kas

It's not a thorough documentation, but might be useful. You want to take the wingtip off and move the aileron tube out the way, no question. You'll also need to remove the wing root fairing and some of the supporting hardware in that location as well.

I also recommend some small plastic "scrapers" you can use to lift the flange up that has all of the connecting screws in it. The dimples in the tank skin screws will naturally want to continue seating in place.

Don't fret it too much. It's a pain, but not the worst possible thing you can do.

 

[DerekS]

Another ER Tank guy

Having done this a few times in the last few weeks...

https://www.amazon.com/dp/B01JBNM9NC?ref_=cm_sw_r_cp_ud_dp_24RK94V0YHVTCKB6RJN8

This little guy is a wonder tool for this job. Use a 3-5" extension in the wing, and a 12" for the wing root bolts, it eliminates the need to move a ratchet back and forth in tight spaces. I used a magnetic nut driver which saved me from losing washers more than a few times. The nut driver isn't needed for removal, but really helps keep getting the bolt started, especially if you have something else in you other hand helping align the holes.

I also leave the aileron rod in the wing, but disconnect it. Its easy to work around if you can move it. No need then to remove the wing tip. Its possible, but really tight to do it with it attached. I have the scrapes to prove it.

If you have ever been tempted by the Aero Creeper, this is also the time to pull the trigger on that

 

[mikelupo]

Having done this a few times in the last few weeks...

https://www.amazon.com/dp/B01JBNM9NC?ref_=cm_sw_r_cp_ud_dp_24RK94V0YHVTCKB6RJN8

This little guy is a wonder tool for this job. Use a 3-5" extension in the wing, and a 12" for the wing root bolts, it eliminates the need to move a ratchet back and forth in tight spaces. I used a magnetic nut driver which saved me from losing washers more than a few times. The nut driver isn't needed for removal, but really helps keep getting the bolt started, especially if you have something else in you other hand helping align the holes.

I also leave the aileron rod in the wing, but disconnect it. Its easy to work around if you can move it. No need then to remove the wing tip. Its possible, but really tight to do it with it attached. I have the scrapes to prove it.

If you have ever been tempted by the Aero Creeper, this is also the time to pull the trigger on that

I did this recently to install the Sky Designs ER tanks on our flying RV-10. Yes, removing the aileron torque tube makes the process much quicker. I did not do that one time and regretted it.

If you don't want to go through the hassle of trying to repair and modify your tanks - I do have two fairly new (40 hours) standard capacity, standard build tanks with Newton Aero 300 fuel caps, inboard return fittings (for SDS or EFII) and outboard fuel bungs (had originally planned on HW outboard tanks). $2500 plus crating and shipping, or pick up in the Atlanta area.

@KatanaPilot I will consider your offer. I will try the repair on my tank first. Will the tanks bolt up to the skin dimples without modification? You got any photos of the tanks? you could email those to me directly. [email protected]

 

[mikelupo]

Having done this a few times in the last few weeks...

https://www.amazon.com/dp/B01JBNM9NC?ref_=cm_sw_r_cp_ud_dp_24RK94V0YHVTCKB6RJN8

This little guy is a wonder tool for this job. Use a 3-5" extension in the wing, and a 12" for the wing root bolts, it eliminates the need to move a ratchet back and forth in tight spaces. I used a magnetic nut driver which saved me from losing washers more than a few times. The nut driver isn't needed for removal, but really helps keep getting the bolt started, especially if you have something else in you other hand helping align the holes.

I also leave the aileron rod in the wing, but disconnect it. Its easy to work around if you can move it. No need then to remove the wing tip. Its possible, but really tight to do it with it attached. I have the scrapes to prove it.

If you have ever been tempted by the Aero Creeper, this is also the time to pull the trigger on that

I like the Aero creeper! Might just do that. I also have the air ratchet and some rather long extensions of varying sizes.

 

[mikelupo]

I did a video about it: https://www.youtube.com/watch?v=0vHQZuK9kas

It's not a thorough documentation, but might be useful. You want to take the wingtip off and move the aileron tube out the way, no question. You'll also need to remove the wing root fairing and some of the supporting hardware in that location as well.

I also recommend some small plastic "scrapers" you can use to lift the flange up that has all of the connecting screws in it. The dimples in the tank skin screws will naturally want to continue seating in place.

Don't fret it too much. It's a pain, but not the worst possible thing you can do.

Thank you for the video! I am checking it out even now. All of you that have replied today are just "plane" awesome..

 

[CharlieWaffles]

I had a similar leak in the right tank and I had to take it on and off about 5 times to narrow it down. I thought it was the corner that was leaking in the tank but it turned out to be the female AN fitting on the inside of the fuel tank. After 6 years the fuel found a way around the proseal and between the AN fitting and the rib. It would slowly weep out and look like it was coming from everywhere but the fitting. Trust me, it took a long time to figure that one out. The fitting now hangs on my hangar wall as a trophy.

All that to say, as a result of this, I had the tank on and off many times. No need to remove the wing tip or the pushrods. There is enough room to get a small socket wrench up there and access all of the bolts. Mind you this is all by feel, so you need to consult the plans on where the attach points are, but once you get on a creeper and get your arm up there, it's not that difficult. It took me longer to get all of the skin screws on and off than to do the bolts. It does take some time, but no more than about an hour to get the whole tank off.

 

[lr172]

I have resealed 6 tanks in the last year (3 were also slosh removal). Suggest pressurizing tank to 1 PSI and use soapy water to find the leak (s). Strongly suggest cutting holes and using vans patch plates to cover for spot repairs. Removing the rear baffle is NOT easy and you risk damaging it. I had to use a lot of heat and had to make special puller spoons to get them off. You cannot just pull it off from the ends; that will bends it at the angles. One of the tanks that I did had the rear baffle installed backwards (no way to seal it at re-install time and likely why he had to slosh it due to the leaks it created), so had to do the entire reseal through holes. It is not that hard; just frustrating. Get a telescoping mirror.

If you are sealing over old proseal, it needs to be cleaned thoroughly with MEK before new sealant. If going over alum, it needs to be scuffed first.

Larry

 

[mikelupo]

Just a follow up. I did manage to remove my tank this past weekend. I found it very frustrating to remove the bolts with the aileron push rod in the way. I removed the wing tip, removed the two push rod bolts and viola, was able to move it out of the wing enough to make it very easy to remove the 18 bolts. I lamented this for months but in reality, it was quite easy with the push rod removed. I also purchased some teflon sockets which prevented my tools from scratching the anodized spar. Oh, I did purchase a battery operated ratchet from Harbor Freight. the smallest they made. It worked flawlessly!

Now that the tank is sitting in my living room...I've identified the leak. I'm going to try the runny proseal (if I can find it to purchase) and a hand vacuum pump to pull a slight vacuum on the tank. I don't see a problem with ~1lb of negative pressure in a controlled environment. While flying over Boston harbor, I noticed that I could see the ribs of my fuel tanks in the right wing. I knew immediately I had a clogged vent line. Probably a lot more than 1 lb of negative pressure. Yeah, no thanks mud dauber! This is probably what caused the leak to begin with. I had already switched to the left tank at that point. Ugh... I've already had one off airport water landing. I don't need a second.

Checklist update. I now put my mouth on the fuel tank vent and blow into the tank before I fly to ensure proper venting.

ps... I found a cooked broken ground to my taxi light when I opened up the wing-tip. That explains the radio noise when I turn them on.

 

[PaulvS]

Just a follow up. I did manage to remove my tank this past weekend. I found it very frustrating to remove the bolts with the aileron push rod in the way. I removed the wing tip, removed the two push rod bolts and viola, was able to move it out of the wing enough to make it very easy to remove the 18 bolts. I lamented this for months but in reality, it was quite easy with the push rod removed. I also purchased some teflon sockets which prevented my tools from scratching the anodized spar. Oh, I did purchase a battery operated ratchet from Harbor Freight. the smallest they made. It worked flawlessly!

Now that the tank is sitting in my living room...I've identified the leak. I'm going to try the runny proseal (if I can find it to purchase) and a hand vacuum pump to pull a slight vacuum on the tank. I don't see a problem with ~1lb of negative pressure in a controlled environment. While flying over Boston harbor, I noticed that I could see the ribs of my fuel tanks in the right wing. I knew immediately I had a clogged vent line. Probably a lot more than 1 lb of negative pressure. Yeah, no thanks mud dauber! This is probably what caused the leak to begin with. I had already switched to the left tank at that point. Ugh... I've already had one off airport water landing. I don't need a second.

Checklist update. I now put my mouth on the fuel tank vent and blow into the tank before I fly to ensure proper venting.

ps... I found a cooked broken ground to my taxi light when I opened up the wing-tip. That explains the radio noise when I turn them on.

Hi Mike,
It's a common place for leaks because it is difficult for the builder to apply a proseal fillet in that location during construction. The fillet is what's needed for a good seal. It would be worth cutting an access hole in the baffle to get access for a repair along that seam from the inside. The Van's repair kit works well and is actually quite easy to do.

 

[mikelupo]

Hi Paul, Thank you for your reply. I wonder, do I have to apply proseal to the entire length of the tank on the inside of that seam or only a distance before and after the leak? I also note that I got soapy water inside. It's evidenced by the fact that even though I've wiped all the soapy water is now off the seam, if I pump some positive pressure, I still see bubbles. I hope that won't affect the proseal. I might have to pull some alcohol through it to dry it out.

 

[Bill Boyd]

Heating pad near the seam? Hair dryer in filler neck? Don't want to damage the sealant you're not replacing. Isopropyl alcohol (hygroscopic and low surface tension) would probably work, too.

With my well water, I'd be concerned with just letting it evaporate and leaving mineral film behind - but I tend to overthink a lot of things.

 

[PaulvS]

Hi Paul, Thank you for your reply. I wonder, do I have to apply proseal to the entire length of the tank on the inside of that seam or only a distance before and after the leak? I also note that I got soapy water inside. It's evidenced by the fact that even though I've wiped all the soapy water is now off the seam, if I pump some positive pressure, I still see bubbles. I hope that won't affect the proseal. I might have to pull some alcohol through it to dry it out.

Hi Mike, the new sealant should go inside along the seam at least a distance either side of the leak because it can travel sometimes. It may be worth proactively sealing the entire length of the seam in that bay though, since it will be open and takes little extra effort, depending on how it looks inside.

The surface to be sealed should be cleaned with a solvent like naptha or Coleman fuel and the metal can be scuffed with a small wire brush the size of a toothbrush.

 

[Vol88]

The Dewalt DCF680 gyro screwdriver will fit inside the -10 wing and has plenty of torque to remove the tank attach bolts, unless Popeye installed them.

In its straight configuration - which I prefer anyway - I can feel the torque almost like a manual screwdriver. The clutch is fully adjustable, so you can snug the bolts down before tightening them by hand.