Rebuilding 1948 fuel selector

[blueldr]

Idaho is bad about fuel leaks. If you get that airplane out of Idaho, your troubles will most likely be over. The only fuel leak I ever had occurred in Idaho. I't a bad place for fuel leaks. They are properly entered in the log book as "Geographic Fuel Leaks" and can be cleared by simply moving the airplane to another state.

[IdahoPilot]

Ha ha, The airplane came from Nevada and California. So I am blaming those locations.

[blueldr]

I'll bet it didn't leak before it got to Idaho !

[Kurt Aichele]

Resurrecting a post.
Just pulled the fuel valve and found cone and body OK, but the "Detent washer" that IdahoPilot spoke about broke on us also. 1948, serial # 18118. Any source for this part? Will also replace the "O" ring as part of the rebuild.

[Bruce Fenstermacher]

Kurt, that is an unobtainium valve. So no parts.

If I saw a good picture of the broken part with some measurements, diameter and thickness and a good idea of the material I might be able to help you out with a part I find near my lathe. Funny thing about that lathe. I can't find a part and I start searching high and low about that area and in an hour or so darn if I don't find what I'm looking for.

[48rwflyboy]

I just bought a used one from Wentworth and it was the exact replacement. About $300 and warrantied if it doesn't work. Great source for hard to get parts. I had the same detent issue and the replacement worked just fine. Don't use fuel lube is my personal advice. Just oil it good in the re-install and observe the order of the parts. You may need a new nitrile o-ring. Very tough job on the 48 Ragwing. This is the valve they shipped me. http://www.wentworthaircraft.com/ Part number 0511122

Wentworth $312 31Mar16.JPG

Order Left to Right Exactly Shown.JPG

[Bruce Fenstermacher]

Is it #3 that breaks? Looks pretty easy to duplicate.

[Bruce Fenstermacher]

Don't use fuel lube is my personal advice.

Why not fuel lube?

Regular oil is gone the minute gas flows through. Not so with fuel lube.

[48rwflyboy]

Is it #3 that breaks? Looks pretty easy to duplicate.

I don't think so Bruce! It is very hard metal that has spring qualities that make the detents snap into position. But someone did make it before but suspect it was stamped out with a very good machine???

[48rwflyboy]

Don't use fuel lube is my personal advice.

Why not fuel lube?

Regular oil is gone the minute gas flows through. Not so with fuel lube.

Bruce, I have used fuel lube before and it doesn't prevent the valve from getting hard to move with time. Also, when you open up the valve, the residue from the grease winds up in the bottom under the tapered valve making it useless. I think it dries up and cakes adding to the stiff valve problem. Saw this on the valve I just removed which had been serviced a few years ago. And that was using just a thin film. I also noticed the detent action is deminished somewhat. Just my opinion though thinking a clean valve works better even without lube.
I have thought forcing a little Marvels MMO backwards through the valve when it starting getting stiff might be a good temporary fix and certainly couldn't hurt anything.

[Kurt Aichele]

Thanks 48rw. This is the exact valve that I have.
Yep, Bruce, #3 is the part that broke. Although, part #4, the "cup" came out the opposite way that the picture shows. On my valve,the spring fits into the cup of #4, and the base, or bottom of the cup rides on the detent washer, if that makes sense. Put a magnet to it and it's steel. Looks to be .045" thickness. Left it at the hangar, so I don't have any specific measurements, and will not be able to get back there for a couple of weeks.

[48rwflyboy]

Kurt, I am fairly sure the #5 spring should not be on the inside of the #4 cup as the valve shown appeared to have never been apart that came from Wentworth until I took it apart in this exact order to clean it (found very little wear on the pin or plug indicating little use or very low time). Also, unless your spring is longer than shown, it will not be as "loaded" against the detent washer making for less "snap" on the selector. Additionally, I suspect the cup facing down against the detent washer actually puts outside pressure on the washer where it should be (if that makes sense). By the way, what kind of wear did you find on the pin? If it is flat on one side, you will obviously lose the detent "snap".

Ernie
48RW

[Bruce Fenstermacher]

I agree with Ernie, the cup should probably be as he found and described.

Before we would make #3 we would want to know if it is hardened. Kurt, taking a file, lightly try to file an edge and see if it cuts. Probably is hardened as the pin likely is.

Just another detail to duplicate some how.

[Kurt Aichele]

Thanks Ernie. I believe the valve was rebuilt in the late 90's by others, so it may not have gone back together correctly. After looking at it closer, it does make sense what you said about the position of #4 part. The pin looked good, no flat spots.
Bruce, when I get back out to the hangar, I'll check it with a file. Thanks for all of the help and input from both of you.

[Kurt Aichele]

Searched around and found what was suppose to be a salvaged fuel selector valve from Wentworth. After checking the valve, it looked identical to my valve except the bonnet style. Took it apart and found the detent spring completely different and the tapered cone to be made of plastic, along with it having only 2 holes instead of 3. This gives me a "Left", "Off", and "Right", but no "Both". From reading several threads, appears to be from a 140. So the search is on again for the correct fuel selector valve or a detent spring. Mine looks exactly like Ernie's pictures. Thought of trying to fabricate a new detent, but appears to be made of spring steel. Looking for ideas/suggestions.