Fuel Selector Repair

[Subsonic]

In keeping with Subsonic’s comments above I offer an off topic case that illustrates his point.
In 1957 a Navy destroyer returning from Asia brought the first case of the Asian flu H2N2, a corona virus.
A Microbiologist recognized immediately it was a new strain and was able to isolate the virus from a sailors blood.
Working with vaccine manufacturers he was able to come up with a vaccine in 3 months. He commented later he was able to that because He was able to bypass the government red tape.

https://daily.jstor.org/how-america-...mic-to-a-halt/

https://en.m.wikipedia.org/wiki/1957...uenza_pandemic

I was researching this because in October 1957 I spent several days in the Naval Training Center San Diego , boot camp, sick bay with lots of others with the same symptoms. The doctor blew off my question about what we had. He said us midwestern (Kansas) farm boys We’re just not use to being around a lot of people. After COVID 19 started I got curious and am now convinced that based on the symptoms and really large number of with the same symptoms we all had the Asian flu.

Gilbert, thank you for that insight. I know of similar events. Not to make this political, but IMO big government doesn't necessarily mean better government. Now, back to shortwings, where I can have some modicum of control over my meager and humble destiny...

Knowing what I know now about the urgency that will follow when the tank runs dry, I will maintain that fuel valve like I change my engine oil. If it decides to get a little grunchy in operation, I know how to drain my tanks and fix that thing.

I also know that it can go from "ok" to "WTF" in two or three operations. Info for those that may be interested...

[SMO22]

So the only difference between the original valve and Aircraft Spruce valve is the elimination of the spring cup washer, and swap the original position washer with the new position washer? Hmmm.

Completely WRONG, you can't turn the original Piper brass plug valve into the Piper plastic plug valve that superceded the original Piper brass plug valve. THEY ARE COMPLETELY DIFFERENT DESIGNS!

Lets make this clear,
1940s through the 1960s Piper used the brass plug or cone valve, Piper part 11383, it has the flat position washer that loses its detent over time and was the reason the AD was released which requires the detent be checked

In the 1970s Piper started using the Piper part number 77413-2 fuel valve, a completely new design valve and it replaced the old 11383 valve, the 11383 with the brass plug and the 77413-2 with the plastic plug are completely different.

In the mid 1980s Piper began using the 6s122 valve and it replaced the 77413- valve.

The aircraft spruce 6749 valve and the Piper 77413 valve are the same valve except for the 6749 now uses the better delrin plug instead of hard plastic that the 77413 valve used.

What you are getting all mixed up is what Mark said of how to convert the Piper 77413 valve into a Maule valve with a BOTH position. You CANNOT DO ANYTHING WITH THE OLD PIPER BRASS PLUG 11383 VALVE except keep on maintaining it when it loses its detents.

What can be done, and ONLY if you are Experimental, is like I have done with the Hatz, it had the Piper 77413 valve in it when I bought it, it neaded a new oring around the shaft, it was leaking fuel, while I had it apart I had a new 6749 valve from Aircraft Spruce ready to install, I noticed the 6749 and the Piper 77413 valve were the same valve, so I just rebuilt the Piper 77413 valve with the new 6749 guts, the new delrin plug replaced the plastic plug and the new orings and it was a new valve.

[SMO22]

All fuel valves can fail, the important thing to take away from this thread, is to know how your selector works and check it before each flight to ensure its working properly. The 11383 valve is notorious for position detent problems, the 77413 plastic plug valve has also failed probably from lack of lubrication, the plastic plug has broken apart inside the valve. I like the Aircraft Spruce 6749 valves delrin plug its stronger and is what I use inside my Piper 77413 valve, it has worked flawlessly for years with no detent problems and it never needs lubrication, the fuel lubricates the delrin plug. I know the valve like the back of my hand, I know how it feels when working properly. Those that use the original brass plug 11383 valve and like it probably do the same thing, those that use that valve and have not had it apart and understand how it works should do it, know the valve and how it can fail, know what it should feel like when it starts going south. Those that have the money and want the valve that is probably the safest regarding detent issues, the newest valves from Allen Univair or Dakota are probably the best. Know your valve and how it feels when working correctly, if it feels abnormal dont fly.


Subsonic's recent lack of detent experience with the 11383 valve validates my feelings on that valve, he stated it went from fine to no detent in one flight. Here is the AD on the 11383 valve that came out in 1960, 60 years ago and still causing accidents, as well as an NTSB report from a pilot that was not as fortunate as Subsonic.





http://ohio.shortwingpiperclub.org/M...s/60-10-08.pdf

[Steve Pierce]

Did they find that the fuel selector was defective?

[marcumb]

What is the torque value for the fuel line connection to the weatherhead fittings in the fuel selector valve?

[Steve Pierce]

I have never seen a torque, I make them snug and line up.

[dgapilot]

While you have the valve apart, might as well replace the detent washer. When it wears, the detent positions are not very positive. Read AD 60-10-08 when putting this together. Compliance with the AD is required every 100 hours.

[PA-16]

Marcumb, if you still have the original valve, you can put a trouble free valve in for 100 bucks, https://www.ebay.com/itm/Valve-Fuel-...2/153830590434

The original valve has put plenty on the wrong side of the grass

[Steve Pierce]

What is the torque value for the fuel line connection to the Weatherhead fittings in the fuel selector valve?

I got to thinking about this and it would be the torque value of a pipe fitting since they are MIP threads into the fuel valve. You just have to be careful not to put torque on the opening in the soft brass fitting sides where it will cave in the fitting. I have done that.

[Lucas F]

As this seems to be a pretty big topic, I thought I would add my recent experience. I had fuel dripping from the inverted flare/weather-head fitting to the fuel strainer inlet fitting. As it seems the old inverted flare weather-head fittings are prone to leaking. Rather than try to repair something that is likely just going to leak again, I elected to replace the inverted flare/weather-head fitting with new EATON NPT weather-head fittings and AN fittings between the fuel tank selector valve and the fuel strainer. When people expienece these leaks, why are they not replacing the old inverted flare fittings with AN fittings. The 37 degree AN fitting are not likely to allow a leak. More rhetorical questions, no answers needed.

I will be replaceing the other inlet fittings and lines to the fuel selector valve as I fly some fuel out of the tanks.

Out with the

10AED714-354B-465F-85BC-CB421D16AEB2.jpeg7D0456C5-185D-4718-9E3D-1F8A40ADF8E4.jpeg

In with the new

46FA1BD9-AB57-4D10-9E8F-257324872EEB.jpeg3B261021-F571-45B3-BDBC-35F02766A002.jpeg

Lucas
N5821H
PA-16 Clipper, S/N:16-437