Replacing Wing Fuel Drains

hamer

hamer

Pre-takeoff checklist
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hamer
I bought a 1946 C120 recently. The wing fuel drains are pretty well rusted. I purchased replacements however I've hear horror stories about these breaking off or destroying threads on removal. Anyone have any tips? Attaching a photo of mine, as you can see it needs to be replaced badly.
 

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We have some good information in our archives at the Cessna 120-140 Association site. Are you a member? Shoot me a PM or an email and I will help...
 
Rob58 said:
We have some good information in our archives at the Cessna 120-140 Association site. Are you a member? Shoot me a PM or an email and I will help...
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Lordy, I really hate asking for a PM/email when we could ALL benefit from the information. This is a bulletin board; it ain't nice to ask for private information unless it is intensely personal.

Jim
 
I would be concerned about the bending around the drain itself, if what is shown is the tank material. Might be a good idea to check it out at the same time.

Does the 140 have the same drain plug down at the fuel valve in the floor? The 150/152 has an stc to change the plug to a drain valve so it can be drained and cleared more often then once a year (or two or three or ...). If the option was there to add it, I would.
 
weirdjim said:
Lordy, I really hate asking for a PM/email when we could ALL benefit from the information. This is a bulletin board; it ain't nice to ask for private information unless it is intensely personal.
Jim
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Jim, no worries my friend! The PM was to discuss the connectivity to the Cessna 120-140 forum. All of my POA buddies are welcome to peruse the Cessna forum and even join our Association. I'm busy building a new website with some great content. Stop by when you can.
 
They may have been installed with fuel lube, and come out easy. This has been a known problem for a long time, long enough that maybe some got smart.

you do know there is a special socket to remove and install the Curtis valve ? ? ? ?
 
Youse gots a rusty steel fitting in an aluminum hole and someone has already tried to get it out only to have the wrench slip. Plus, it's skrewed into a gas tank and surrounded by fabric.

Fun project!!!!!

You can't use a torch. Penetrating oil won't hurt. Won't do much good, but it won't hurt. Can't bang on it too hard without denting the tank.

Prolly just gonna have to suck it up and put a 6 point socket on it and gentle work with an impact. Run it both ways to work it loose. But in the end, be prepared with a helicoil.

Oh, I ain't no A&P, so all my advice is wrong.
 
Capt. Geoffrey Thorpe said:
Youse gots a rusty steel fitting in an aluminum hole and someone has already tried to get it out only to have the wrench slip. Plus, it's skrewed into a gas tank and surrounded by fabric.
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I think your borrowing a lot of trouble, did you look at the picture?
I see a rusty spring, and a leaking fitting.

I'd place a catch basin under it and have a go with a 6 point socket, I don't see that anyone has buggered the fitting. It should come right out.
 
I hadn’t thought about an impact, that’s probably the safest way if it’s stuck. My biggest concern is on the left tank it looks like there’s something leftover that might get in the way as I’m trying to remove it (photo attached). I really don’t want to damage the fabric.

Does a socket really fit over it? I guess I could grind it down if it doesn’t.
 
hamer said:
Does a socket really fit over it? I guess I could grind it down if it doesn’t.
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Yes, a 11/16 or3/4 deep 6 point. no impact, just a long breaker bar.
 
Tom-D said:
That fabric is loose around that drain. it needs to be tightened, and an inspection hole grommet installed.
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Do you have photos on how that should look?
 
It’s a brass fitting in an aluminum tank. What’s the problem?
 
hamer said:
The logbook says the stits method.
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You got lucky,,here is what I would do first. Using a hot airgun, slowly heat the area around the drain. Be careful don't blister the paint. when the ceconite gets hot it will shrink, when it does, remove the heat quickly. it should tighten the fabric, and remove the wrinkles
 
You're probably better off leaving the fabric alone. It'll look worse after you blister the paint. BTDT!
If you're determined to tighten it? Use an electric iron and hold a piece of parchment paper between iron and paint.
 
I'm trying to remove and replace it, not tighten it.
 
hamer said:
I'm trying to remove and replace it, not tighten it.
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The tighten comment was about the surrounding fabric. If you don't have any fabric experience? Now probably isn't a good time to learn on your own.

The quick drain should come out. If you're wary of it ask your mechanic to do it or to guide you through it.
 
teejayevans said:
Yikes! I don’t think brute force is the way to go.
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How many have you done?
This is typical of a 70 year old tank fitting, I've found they usually come right out. just don't bang on them, that will place more stress on the tank than a steady pull.
 
Stewartb said:
You're probably better off leaving the fabric alone. It'll look worse after you blister the paint. BTDT!
If you're determined to tighten it? Use an electric iron and hold a piece of parchment paper between iron and paint.
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Difficult to get an iron on the fabric where it is needed in this case, plus any iron that is hot enough to shrink the fabric will melt the paint. I guess you found that out.
the hot airgun is much better in cases like this, because the heat the fabric and paint at the same time, and the fabric will shrink before the paint melts. When that happens, quit heating take the gun away.
 
Clip4 said:
Safety first.
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Anyone stupid enough to use a torch on anything like this, deserves what they get, call it gene pool purging.
I occasionally weld on fuel tanks, so the first action in doing so is to remove tank from aircraft.
 
Tom-D said:
Anyone stupid enough to use a torch on anything like this, deserves what they get, call it gene pool purging.
I occasionally weld on fuel tanks, so the first action in doing so is to remove tank from aircraft.
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My first action would be grounding the plane and draining the fuel from the tank.
 
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Tom-D said:
Anyone stupid enough to use a torch on anything like this, deserves what they get, call it gene pool purging.
I occasionally weld on fuel tanks, so the first action in doing so is to remove tank from aircraft.
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yup.....be careful whacha post. ;)
 
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