Quick drain on bottom of Fuel Selector
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C170U2
- Posts: 436
- Joined: Sat Dec 22, 2012 4:30 am
Re: Quick drain on bottom of Fuel Selector
I was going to do this to my 170A but gave up. The plug was too messed up to allow me to remove it while installed in the airplane. I am holding off on doing it till I have to take out the fuel selector valve one day. I would think a log book entry would be fine for this one.
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GAHorn
- Posts: 21283
- Joined: Fri Apr 12, 2002 8:45 pm
Re: Quick drain on bottom of Fuel Selector
A question I sometimes get about this is : " Can the pipe-plug be removed and a quick-drain installed without completely draining the airplane of fuel?"
Answer: Yes. If you turn the fuel selector valve OFF... the internal check-balls will close and shut off all fuel from flowing out of the valve including the valve-drain. However, be alert to the fact that any fuel inside the valve (an ounce, perhaps) and any fuel in the gascolator which is above the valve in the 3-point stance, may "back-drain" and exit the drain. So, drain your gascolator first... and be prepared to see a few tablespoons of fuel come out of the valve when you remove the plug.
Also, do not use Teflon tape on the install. (It can/will shred and might allow particles to enter the fuel system which can plug carburetor passages.) A small "dab" of Permatex No. 2 sealant on only a couple of threads of the new drain valve is all that is required, ... and be careful not to overtighten the new drain to avoid cracking the valve body.
REmember: it's only gravity fuel pressure down there. You don't need much more than finger-tight (plus perhaps a 1/4 turn.)
Answer: Yes. If you turn the fuel selector valve OFF... the internal check-balls will close and shut off all fuel from flowing out of the valve including the valve-drain. However, be alert to the fact that any fuel inside the valve (an ounce, perhaps) and any fuel in the gascolator which is above the valve in the 3-point stance, may "back-drain" and exit the drain. So, drain your gascolator first... and be prepared to see a few tablespoons of fuel come out of the valve when you remove the plug.
Also, do not use Teflon tape on the install. (It can/will shred and might allow particles to enter the fuel system which can plug carburetor passages.) A small "dab" of Permatex No. 2 sealant on only a couple of threads of the new drain valve is all that is required, ... and be careful not to overtighten the new drain to avoid cracking the valve body.
REmember: it's only gravity fuel pressure down there. You don't need much more than finger-tight (plus perhaps a 1/4 turn.)
'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.
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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busav8or
- Posts: 232
- Joined: Mon Nov 23, 2009 11:37 pm
Re: Quick drain on bottom of Fuel Selector
OK, this thread got me curious about a drain under the fuel valve under 10B. I crawled under and found that there is no inspection port under my valve and no way to access the valve without cutting a new one! I could see the bottom of the selector but it was a good 6 inches from the nearest port. 4410B is a '55 B model (ser #26754) so shouldn't it have access? Anyone else seen this?
Former Caretaker of N4410B '55 170B
s/n: 26754
s/n: 26754
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johneeb
- Posts: 1542
- Joined: Thu Jun 26, 2003 2:44 am
Re: Quick drain on bottom of Fuel Selector
Mine is just like the picture in the parts manual except the belly skin plug, Number 8 in picture, has a hole for the quick drain. My serial # is 25501.
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John E. Barrett
aka. Johneb
Sent from my "Cray Super Computer"
aka. Johneb
Sent from my "Cray Super Computer"
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busav8or
- Posts: 232
- Joined: Mon Nov 23, 2009 11:37 pm
Re: Quick drain on bottom of Fuel Selector
I have the #6 port next to the #8, but no #8!
Former Caretaker of N4410B '55 170B
s/n: 26754
s/n: 26754
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