What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Leaks

V

Vlad

Well Known Member
Topped both tanks, checked fuel flow, calibrated dipstick. First day there was nothing. Came in three day and saw this :eek: Also there is slight haze of blue dye on both drains. Fuel level didn't change which is strange. How to eliminate the seepage?


Tankleaks.jpg



Tanks were done three years ago and pressure tested.
 
put a glob of proseal over the screw head, wipe the drains off and see if it comes back

did you put any fuel seal butter on the cork bark gasket?
 
Last edited:
The most effective...

Remove the cork gasket (any rubber gasket too) & pro-seal the cover on. Dip the screws in pro-seal also.

L.Adamson --- RV6A
 
Over the long term, I think you'll be happiest if you pull the access covers, remove the cork gaskets, and reapply the covers using proseal alone to seal them. Then, with everything clean, apply a bead of proseal over each screw.

While you have the fuel access covers off, you might as well give the fuel quantity senders and their screws the same treatment.

On the drains, use a little more fuel lube and tighten 'em just a bit more.
 
With my first 100 hours, I have had to pull the left drain twice. It is just **** from the build that gets stuck on the o-ring. Van's sell new o-rings by themselves, but you still need a complete drain plug to swap them out without draining your tanks.

I am using the cork gasket without pro-seal. It has not started leaking yet. But, I do know it will start leaking at some point. Then I will go back with the proseal option. I also have allen head cap screws to replace the phillips head screws when I do the reseal.

BTW, I have pulled the fuel filter screen twice, always clean.
 
Vlad,

I put a dab of proseal on the inside of the tank over the nutplates to seal them from that side. I'm using the cork gaskets with some fuel sealant and allen-head screws. I did have to tighten these screws slightly after about a year and a very small weep, but no leaks in the past 18 months.

greg
 
Sounds like pro-seal is the way to go here. I suspect the drains might just be stained by all the fuel we left on them during the initial fill...maybe. Either way, I have a nice big tank to store all your fuel for you!!!:D:D:D
 
You are not alone Vlad - I had almost identical leaks to yours when I first filled up the tanks on the Val. Emptied them out, ditched the cork seals, and went Pro-seal all around - no more leaks. Someone at the factory told me to do that....

Many have also used allen-head screws instead of the Phillips to make removal easier if there is a next time.

Paul
 
Ironflight said:
You are not alone Vlad - I had almost identical leaks to yours when I first filled up the tanks on the Val. Emptied them out, ditched the cork seals, and went Pro-seal all around - no more leaks. Someone at the factory told me to do that....

Many have also used allen-head screws instead of the Phillips to make removal easier if there is a next time.

Paul
Click to expand...

Recently I removed those plates. After 8+years of being prosealed in (no cork, never a leak) it was a pleasant surprise how easy the screws came out with the lithium 4v mini electric screw driver from Sears. The plates were stuck to the rib quite firmly but a flexible metal putty spreader finally did the job. It had to be driven with a hammer to cut the sealant but it worked without damaging the plate or the rib.

It seems to be fashionable to use as little sealant as possible. The initial image of Vlad's leak is very neat and clean - except for the blue stain. My plate did not look that nice but it did not leak. There was proseal under every screw head and around the edge of the plate itself.

For sure with experience a tank can be built with minimal sealant but for most builders who do this just one time, the first time, more sealant is better.

(about ready to close both tanks - almost one quart plus 2 tubes used so far)
 
Slathered up the cork seal with proseal on both sides and dipped/capped the screws with proseal....no leaks so far.
 
Thanks you all for the tips. Proseal and allen head screws will be there eventually. Somebody suggested to leave as it is for now and watch. I wiped out stains and almost a week there is no sign of blue dye on covers. However the drains were blue again (yes I drained some fuel) they are tight but where the dye coming from? It was cold in the hangar.


rightdrain.jpg



leftdrain.jpg
 
I used the cork and the tanks leaked like yours

It was a new experience for me and fat dumb and happy I filled all four tanks and went home. When I returned the next day I had a very large pool of fuel on the hangar floor under the entire airplane.

DO NOT EVEN BEGIN TO THINK YOU CAN SLATHER ON A LOAD OF PROSEAL AND ALL WILL BE WELL. If there is fuel on the surface the proseal will not cure properly (it will stay tacky - soft) and the leaking will be reduced but the seepage will continue.

It is best to get enough 5 gal. gas containers from WALMART or an auto parts store and drain the tanks and clean all fuel from the seal area as the first step in correcting the problem. I used rubing alcohol to clean the fuel off.

After that I would follow what some of the successful builders above have done - get rid of the cork gasket and use proseal at the interface, at the egdes, under & over the screws and allow it to cure before refilling the tanks with fuel.

Bob Axsom
 
Fuel drain seals leak when not properly seated

Sometimes this comes from foreign material in the tanks rushing to the drain when you draw your sample and lodging in the seal interface sometimes it is just the way the friction of the drain affects the closure at a particular time. Sometimes they just don't seal properly when casually opened and released to close. When I had my Archer on lease back to The Flying Club for a few years, renters would often not close the drain properly and the blue die in the 100LL fuel would stain the wheel pants very badly. Usually I could get it off with a cleaner/wax. Don't replace them it is just the nature of the beast.

Three things I try when a drain hasn't sealed properly is push it in and let it got abruptly so it has some force in the closure process, I pull down on the drain to force it closed or I rotate it to change the seat position.

Usually if a drain is leaking (not closed) you can wait a short time and lightly touch the drain and you will find a slight blue wetness on your finger. Reseat and repeat until your finger comes away clean and dry. If you get any wetness it will continue to leak for sometime depending on the size of the leak.

I change configuration for racing and remove the tip tanks. This requires draining the tanks and I remover the drain plugs to accomplish this task. I have never had one leak through the pipe threads and I see no evidence of that in your installation.

Bob Axsom
 
Last edited:
Vlad,

Looks to me like your drain has a leak around the threads. If it were simply a seal leak, the top part of the drain would not have blue on it. I would drain the tanks, pull the quickdrain, put some liquid teflon or other sealant on it, and screw it back in. If you have a helper, you can just pull the drain, and have the helper hold a finger over the hole while you add the sealant. Alternatively, it might seal if you just tighten it a bit but be careful not to overtighten.

greg
 
Hey Vlad,

Do yourself a favor and get an extra fuel drain and keep it as a spare with a fresh O ring. If you get a leak like this, the first and easiest thing to do is swap out the drain. Let out a little fuel (which is pretty much unavoidable) during the changeover, which will usually clear out any debris in the bottom of your tank. I use Fuel Lube on the threads but whatever works for you. And if that fixes it, put a new O ring on the spare drain for the next time.

Good flying!
 
Leaks no more

Greg,
Followed your advice on drains, unscrewed, put some EasyTurn on threads, blue haze stopped.

Changed screws and resealed, topped tanks, third week no blue dye.
Problem solved I think. Gaskets will stay for couple years.


coverfixed.jpg
 
Last edited:
Another sealant that works great on threads and is fuel proof is Seal-Tite. Aircraft Spruce sells it. I use it in my molding business to seal fluid lines that get up to 500 degrees F. It works when other sealants won't.
 
Vlad said:
........... I wiped out stains and almost a week there is no sign of blue dye on covers. However the drains were blue again (yes I drained some fuel) they are tight but where is the dye coming from? ............
Click to expand...

Vlad, to answer the question: The leak is so very small that the fuel never drips onto the floor, but merely evaporates, leaving the blue dye behind. Similar to salt water evaporating, and leaving the salt behind.
If the leak were a bit bigger, the fuel would drip on the floor, then evaporate, leaving a blue dye stain on the floor.
 
Hex screws

Hey Vlad,

Can you give me info on the hex screws - size, where you got them etc?
I should have the left wing finished by end July.

Thanks,

Tom
 
Last edited:
You must log in or register to reply here.
Back
Top