Fuel level floats sunk 55 C170B

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JohnNielsen
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Joined: Tue Sep 14, 2010 10:21 pm

Fuel level floats sunk 55 C170B

Post by JohnNielsen »

It appears the floats no longer float after 25+ years most of them dry. I see that Aircraft Spruce has replacement floats and gasket. It looks like a simple job to drain the tanks, remove the gauge from the tank, replace the float and gasket and reinstall. What other warnings or catches am I likely to find or want to avoid?

Thanks, John
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c170b53
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Re: Fuel level floats sunk 55 C170B

Post by c170b53 »

Have the tanks been empty lately? When my plane was out of action some time ago the floats stuck to the bottom of the tank. I did end up changing one with the Spruce part, I guess you can check the gear train is free and not seizing up, other than that once out it's easy to see whether the float has any flotation to it :D
Jim McIntosh..
1953 C170B S/N 25656
02 K1200RS
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170C
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Re: Fuel level floats sunk 55 C170B

Post by 170C »

John, check the forums as there is a wealth of data there on replacing the floats if that becomes necessary. As I seem to remember the recommended replacement for the old cork float is now a plastic type float.
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stogie17
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Re: Fuel level floats sunk 55 C170B

Post by stogie17 »

My fuel float was sticking and at annual it was pulled and found to had jumped gears so to speak and with some tinkering works fine for now. You might pull it and see what problem is. I had ordered new gauge but didn't need it.
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JohnNielsen
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Re: Fuel level floats sunk 55 C170B

Post by JohnNielsen »

I bought new 'plastic' floats and a replacement gasket from Aircraft Spruce, removed the gauges, found the gears 'sticking' due to 'crud' deposited to them when the tanks sat dry for over 20 years. Cleaned them up, changed floats and reinstalled. Works fine...but I had the scare of my life...

Full tanks of fuel..no problem, just remove the sump drain valve and drain the fuel into a filtered clean transfer tank. Remove old gauges..no problem. Old gasket material sticking to the cabin side neck of the gauge receiver hole. Metal scrapers would not quite get it all off, so I grab my trusty dremmel with the appropriate abrasive/cleaning pad and begin removing old gasket material. Near the end of completing the second tank, with my head positioned about 10 inches directly in front of the opening and carefully working the dremmel around cleaning the surface, I see sparks from the tail vent area of the dremmel and realize I am operating this live spark inches away from the mouth of a 17.5 gallon fuel vapor bomb!!! With a massive pit in my stomach upon realizing how close I came to torching my face off and likely surviving the most horrible injury one could imagine, I quickly removed the tool from the plane and sat down and had a beer (or two). I woke up that night and the next with nightmares of the event. More scary than the day I had to spin through 7500' of clouds with my 1947 C140 and recover under an overcast base only 700' above the ground.
John
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GAHorn
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Re: Fuel level floats sunk 55 C170B

Post by GAHorn »

Fuel tank work is inherently dangerous and only air-driven tools or hand tools should be used and even then....sparks and static can cause discharges.
Flooding the tank with CO-2 and or Nitrogen carries it's own hazards as well (asphyxiation).
Wear natural fibers (no synthetics, not only for static reasons but also because polyester melts to skin when it burns) and a face shield, and keep a shop-fan directed towards the work and yourself. Don't forget to have a helper keep an eye on you and a fire extinguisher handy.
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
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