Fuel tank leaks

9Abuilder · #1 09-17-2019, 09:24 AM

My quick- build fuel tank has developed a leak after only 12 hours of flying. The leak appears on the right tank at the most inboard rib (under the wing root fairing). Note: I cleaned the fuel leak from the affected area and started the engine. After less than five minutes the fuel had leaked from the same crimp in the wing rib and ran down along the access plate. Looking for others with similar issue and how they corrected it.

Thank you for any help.

airguy · #2 09-17-2019, 09:28 AM

If it's leaking that quickly, it should be easy to clean it off and pinpoint exactly where it's coming from. If it's local to the most inboard rib you should be able to pull the access plate (easier to do with the tank off the wing, by far) and apply more proseal to the area internally once you identify where it's leaking.

Paul 5r4 · #3 09-17-2019, 10:14 AM

I had a persistent leak in my right tank. Last year at Petit Jean AK fly in I had planned to go from there to visit a high school friend in KY. On Saturday afternoon I walked up to my plane and saw a small puddle under the right side. It was the first time liquid fuel had actually reached the ground. I scrubbed the trip and flew home the next day. I had been wrestling with this for a long time. I removed the tank and sent it to Paul Beck of WEEP NO MORE. Not cheap.... it hasn't leaked a drop since and I'm positive it won't leak again. I think if I was building tanks today, I'd get them both to the point of putting the back baffle on then send them for him to seal and close. I don't know his process but it works.

In your case, I agree with Greg. You have a big access hole to get at it.

BlackhawkSP · #4 09-17-2019, 11:03 AM

Quote:

Originally Posted by 9Abuilder

My quick- build fuel tank has developed a leak after only 12 hours of flying. The leak appears on the right tank at the most inboard rib (under the wing root fairing). Note: I cleaned the fuel leak from the affected area and started the engine. After less than five minutes the fuel had leaked from the same crimp in the wing rib and ran down along the access plate. Looking for others with similar issue and how they corrected it.

Thank you for any help.

Join the club !!! My QB RV-10 started to leak in the exact same spot after about 40 hours of flight time and a 30 THOUSAND DOLLAR PAINT JOB !!!! Needless to say I was disappointed. Of course Van's said that they will repair it, but I really don't want to cut the paint on all the screw heads and take everything apart. The folks that do the QB's apparently do not prep the parts at all before adding the pro seal during the build. Any residue left on the parts before the sealant just gives a path for the solvent (the fuel) to find it's way under the sealant to the outside (my opinion). I'm going to try first sealing from the outside (with copious preparation of the AL surfaces. After that I'll try and go through the fuel sender port to seal from the inside. It's slow enough that it's more annoying than anything at this point, but it still torques me off. Last resort will be to pull the tank.

I guess the lesson learned is to mount the fuel tanks after paint, so that the screws are not painted. That would make the fixes later on less of a PITA.

9Abuilder · #5 09-17-2019, 05:44 PM

Thanks to those who replied. Van?s is currently out of tank sealant, so I will let you know how the repairs go in a couple of weeks, when they get more in.

Mark33 · #6 09-17-2019, 06:35 PM

Quote:

Originally Posted by Paul 5r4

I had a persistent leak in my right tank. Last year at Petit Jean AK fly in I had planned to go from there to visit a high school friend in KY. On Saturday afternoon I walked up to my plane and saw a small puddle under the right side. It was the first time liquid fuel had actually reached the ground. I scrubbed the trip and flew home the next day. I had been wrestling with this for a long time. I removed the tank and sent it to Paul Beck of WEEP NO MORE. Not cheap.... it hasn't leaked a drop since and I'm positive it won't leak again. I think if I was building tanks today, I'd get them both to the point of putting the back baffle on then send them for him to seal and close. I don't know his process but it works.

In your case, I agree with Greg. You have a big access hole to get at it.

I had a leak on one of my tanks on my first -7 and I sent it to Paul for a repair. He did a great job and it never leaked again. On my current -7 build I did a preemptive strike on my quick-build tanks and sent both of them to Paul so that he could work his magic on them. I?m still in the building process so I haven?t had a chance to check them out, but I have full confidence in Paul?s work and I?m sure I won?t have any fuel tank leaks for the life of the airplane. Paul is a super nice guy to work with and I would highly recommend him and the service he provides to anyone who?s having fuel tank leaking problems.

gmohr · #7 09-17-2019, 08:39 PM

I just did this to my left tank on my 6A. Took the tank off, cleaned all the old
sealant off the outside, removed the inspection panel, bought Pro-Seal from
Aircracaft Spruce, mixed up and resealed the entire rear baffel bot rears of the
sides and replaced the inspection port with a nice 2 beads of Pro-Seal and then
pressure tested the tank. No leaks. I have now filled the tank twice and no
leaks. Yes it is messy and time consuming, but if I can do it anyone can. Good
luck with your leak.

wnplt · #8 09-17-2019, 09:01 PM

I had my 7 painted with the tank screws backed out in case I ever need to remove the tanks. Mine is a standard build so hoping it never leaks.

Steve Barnes · #9 09-18-2019, 08:40 PM

If it is necessary to remove the screws assuming they are painted in place. use a pointy tip exacto and carefully cut around each screw before removing them. A step further would to get matching paint and brush a small dab in each hole before reinstalling the screws.

9GT · #10 09-19-2019, 08:30 AM

From reading all the posts about quick build tanks developing leaks, I decide to do a preemptive strike on the RV-9A project I bought. I opened the tanks up, re-sealed everything inside, and extended the tanks by 3 gallons. You can check out my documentation on the process and what I found in the thread below. My belief is that its not a matter of if the tanks will develop a leak,,,,but when will they start leaking. I was not at all happy with what I saw when I opend the tanks up. http://www.vansairforce.com/communit...d.php?t=158234