Louavul

Louavul

Well Known Member
Wonder if anyone has seen this and/or is it of concern.
Today when sumping my tanks, the left tank was clean, no debris, water, pale blue, etc, the right tank sample was a deep navy blue color. like a new pair of jeans , no debris, water, etc. Took a second sample and it was practically clear as was fuel from the gascolator.
The last time I flew, Nov 8, there were no issues. The last time I topped the tanks was mid Oct at a fairly busy west Texas FBO, this, the last leg of a 2k mile round trip.
My thoughts are; why only the right tank, left has the same fuel; should I drain the tank and dispose of the fuel; add some "new" fuel to blend with the blue stuff or just move on as if "this happens sometimes"?
Appreciate any thoughts.
 
How much fuel did you sample out of the dark blue tank? That (the dark blue sample) is what you might get if you took a small sample out of a tank that had a very slow leak in the drain. When the fuel evaporates, it leaves the blue dye behind. When you drain the quick drain the next time, all that dye is washed into your sample.
 
Kyle: interesting idea, haven't noticed any drips but if it was slow enough allowing evaporation maybe so, I'll look closer, Thanks
 
I had the same thing happen a few months ago, but it took several full samples until it was the right shade (started as a deep blue, successively got lighter). BOTH tanks. AND my buddy on the field had the same thing, reported to me a few weeks later. So probably not, in our case, 4 simultaneous, self-sealing slow leaks in fuel drains. Your case may be different, but it's weird that you see the same or a similar problem.

Wonder if a vendor somehow put too much dye in their process for a while?

Zero issues in flight, so I got that going for me. Which is nice.
 
I'm thinking y'all nailed it as subsequent samples were normal.
This just sort of caught me off guard. Never would have thought of a "moist" sort of leak showing this sort of thing. I'll fly the fuel out of that tank tomorrow and replace the sump drain.
Many Thanks!!
 
Fuel color

Did you add anything to fuel, marvel mystery oil will leach out the blue color and make the fuel almost clear?
 
Louavul said:
I'm thinking y'all nailed it as subsequent samples were normal.
This just sort of caught me off guard. Never would have thought of a "moist" sort of leak showing this sort of thing. I'll fly the fuel out of that tank tomorrow and replace the sump drain.
Many Thanks!!
Click to expand...

I just told you that 4 separate drains on 2 different airplanes had a similar problem, so at least in our cases, it is probably NOT the drain. Maybe it is in yours.

Why not just keep flying, look for signs of a leak and change it if/when you confirm you have one? Rather than replacing things that may not need replacing and introducing possible MIFs?
 
RV7A Flyer said:
I just told you that 4 separate drains on 2 different airplanes had a similar problem, so at least in our cases, it is probably NOT the drain. Maybe it is in yours.

Why not just keep flying, look for signs of a leak and change it if/when you confirm you have one? Rather than replacing things that may not need replacing and introducing possible MIFs?
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I had a slow leak in the drain and it was quite obvious - the blue stain on the ground was difficult to miss. I agree with seeing how you go before changing anything if you don't have evidence pointing to the drain having failed. Changing the drain isn't too difficult, but you will get fuel all over your hands and it's not without risks of igniting that fuel.
 
FWIW, i've seen large variations in the amount of colorant added to 100LL in the last year. Everything from a surprisingly dark blue to almost clear. So there may be multiple things going on.
 
Snowflake said:
FWIW, i've seen large variations in the amount of colorant added to 100LL in the last year. Everything from a surprisingly dark blue to almost clear. So there may be multiple things going on.
Click to expand...

Agreed. I just filled up three 55 gallon drums to bring to my home and had to look at it closely when I started to fill because it only had a light blue tint to it compared with the darker blue I had seen when I filled my plane at another airport a few days before.
 
Pilot135pd said:
Agreed. I just filled up three 55 gallon drums to bring to my home and had to look at it closely when I started to fill because it only had a light blue tint to it compared with the darker blue I had seen when I filled my plane at another airport a few days before.
Click to expand...

I guess we need to get the GAMI guys to add this to their list of things G100UL must do to "match" 100LL - have random variations of fuel coloration! :D
 
Leaking Sump Valve

Steven,

Likely the sump valve is leaking a bit. The dye accumulates in/on the valve as the gas evaporates. Makes for a dark blue sample as it rinses off when you pull a sample. Look for any blue drip stains on the ground. The o-rings in the valve are replaceable, and the valve assemblies are inexpensive. I get about two years out of a set of o-rings.

Cheers,

Vac
 
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