When I repair one of these, I over size the stripped hole to the next pipe thread, then plug it with a pipe plug, grind flush, then drill and thread back to standard.
It's like making a threaded bushing.
wing fuel drain threads stripped!
Moderators: GAHorn, Karl Towle, Bruce Fenstermacher
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edbooth
- Posts: 498
- Joined: Wed Nov 24, 2004 3:03 am
Re: wing fuel drain threads stripped!
One of the problems causing the stripped threads, is maybe a drain with the wrong type threads was screwed in there. My 53 model has a fitting with straight threads that seals with an "o" ring. If someone tries forcing a tapered pipe type fitting in here, guess what happens ? 
Ed Booth, 170-B and RV-7 Driver
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T. C. Downey
- Posts: 548
- Joined: Sat Jan 26, 2013 5:58 am
Re: wing fuel drain threads stripped!
the 170 came from the factory with Curtice drains with a 1/8th pipe thread.edbooth wrote:One of the problems causing the stripped threads, is maybe a drain with the wrong type threads was screwed in there. My 53 model has a fitting with straight threads that seals with an "o" ring. If someone tries forcing a tapered pipe type fitting in here, guess what happens ?
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GAHorn
- Posts: 21297
- Joined: Fri Apr 12, 2002 8:45 pm
Re: wing fuel drain threads stripped!
Actually, they had/have a 7/16-20 thread, and the current replacement part is a Saf-Air CAV-170.T. C. Downey wrote:the 170 came from the factory with Curtice drains with a 1/8th pipe thread.edbooth wrote:One of the problems causing the stripped threads, is maybe a drain with the wrong type threads was screwed in there. My 53 model has a fitting with straight threads that seals with an "o" ring. If someone tries forcing a tapered pipe type fitting in here, guess what happens ?
http://www.aircraftspruce.com/catalog/a ... key=490490
'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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T. C. Downey
- Posts: 548
- Joined: Sat Jan 26, 2013 5:58 am
Re: wing fuel drain threads stripped!
I ordered those and they do not fit the 48's tanks. I know my tanks are out of the box stock. as were my other 48's tanks.
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edbooth
- Posts: 498
- Joined: Wed Nov 24, 2004 3:03 am
Re: wing fuel drain threads stripped!
Don't know a lot about the 48''s , I know they probably used some left over 120/140 parts.T. C. Downey wrote:I ordered those and they do not fit the 48's tanks. I know my tanks are out of the box stock. as were my other 48's tanks.
Ed Booth, 170-B and RV-7 Driver
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GAHorn
- Posts: 21297
- Joined: Fri Apr 12, 2002 8:45 pm
Re: wing fuel drain threads stripped!
OK...yeah, the 48's used 120/140 tanks.
'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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rhouse
- Posts: 3
- Joined: Tue Feb 11, 2014 5:48 pm
Re: wing fuel drain threads stripped!
I had this problem on a C140 once, and was able to repair the tank by cleaning the threads well, then brushing a coat of JB weld over the threads. I then installed the new drain valve after coating its threads with wax.
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