Cubcrafters allen fuel valve
- Thread starter bgriffel
- Start date
mike mcs repair
Registered User
chugiak AK
throw it in a can of gas for a day... O-rings should swell back up...
used Univair valves do the same thing.... Stoddards has replacement metric O-Rings in stock for Univairs valves
used Univair valves do the same thing.... Stoddards has replacement metric O-Rings in stock for Univairs valves
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Steve Pierce
BENEFACTOR
Graham, TX
I have replaced the o'rings before but do not remember them being metric.
http://www.supercub.org/forum/showthread.php?34046-Univair-Fuel-valve-U-491-947
http://www.supercub.org/forum/showthread.php?34046-Univair-Fuel-valve-U-491-947
MS29513-114 is the correct P/N o ring. additionally this valve is prone to leaking if left inactive for a period..(Rebuild) so replace those if you have the valve and have fuel removed from the system for some time... Other than that the valve is very nice.
****Be sure to be ready to catch the two springs and 4 balls as you slide out the center piece!
****Be sure to be ready to catch the two springs and 4 balls as you slide out the center piece!
Charlie Aileron
FRIEND
4GA4 Chatsworth, Georgia
Did Allen Aircraft go out of business? I've had an Allen fuel valve on back order from Aircraft Spruce for nearly three months. Checked with customer service just today and they still do not have the valve.
Charlie Longley
MEMBER
Anchorage, AK
Thats too bad! It's a pretty good valve.
Steve Pierce
BENEFACTOR
Graham, TX
Charlie, Got my back ordered Allen valve for Bill Tracy's Cub from Aircraft Spruce yesterday. I am going to put the Dakota Cub valve in mine, I like that "Both" position for when I forget to turn my brain on. 8)
Charlie Aileron
FRIEND
4GA4 Chatsworth, Georgia
Great, I am glad you got yours. I couldn't wait any longer so I cancelled my back order and installed the old style brass valve. I could never get Spruce to give me any idea when I would get the valve.
Steve Pierce
BENEFACTOR
Graham, TX
The Allen valve has an O'ring in the cone at each hole. Did you figure out a way to seal a new hole? I have drilled the original valves but ruined an Allen valve trying. If you have a way I can save the valve I have.
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j5mike
Registered User
North Alabama
I opened the hanger door one morning to the smell of AV gas. It had filled the belly pod and ran down the fuselage because the O-rings had exceeded their useful life. Anyway, I ordered a new Allen Valve from Spruce (05-29500) If was configured with two open ports and two closed ports. It took some figuring but we were able to drill one of the ports to make it a Right/Left/Both/Off. It could only be drilled one way without ruining the valve but that was 1-1/2 years ago and I can't specificly remember how we did it. I just held the valve up in position to see which port needed to be open and drilled accordingly. Cant say for sure but it seems like we drilled through the valve via one of the existing holes but don't clearly remember what exactly we did. I remember putting the handle on it and studying the fuel travel to get it right but worked like a charm and several $$$ cheaper.
PS, I could have just replaced the O rings and come out better but didn't know that until I removed it and took it apart.
PS, I could have just replaced the O rings and come out better but didn't know that until I removed it and took it apart.
Charlie Aileron
FRIEND
4GA4 Chatsworth, Georgia
The one's I have seen also have the 'O' ring on all three ports even the one that is not drilled. If you are careful you can back drill the third port without damaging the 'O' ring. It was the experimental two port valve that was back ordered for so long. Can't afford the certified one!
Tgskillskill
FRIEND
Fairbanks, AK
Thanks for this thread, finding the correct o-ring p/n's listed here sped up my annual for sure! I do wish we had stumbled on the post before pulling the center piece though, and spending the next 30 minutes looking for tiny springs and balls that shot all over the place.
Did want to mention one or two things we found, in regards to the Allen valve listed above (82829/6S1008 ). Last year during my annual, with the gascolator apart (standard Piper/Univair/not a Steve's)/checking the screen, we found that the off position didn't stop the flow of fuel entirely. Mostly, but not all the way. There was a steady, somewhat fast dribble that continued. We didn't investigate further as it was not entirely alarming, and I'm always on both anyhow.. Plus, full fuel in the tanks and nowhere to offload solidified the decision not to investigate further. I kept it on my squawk list though, and here recently during this years annual we decided to investigate. And I am so glad we did.
First finding. On the edge of life and cracking, MS29513-114 o-rings. These are the (2) 5/8" diameter ones on each end of the fuel selector shaft. I believe it would not have been long before I started having a fuel seep/leak around the selector valve, which if one totally tore and cracked in the middle of nowhere, would be an absolute PITA. Especially when you think it's a damn $0.50 part that would be stranding you. If you haven't ever changed these, maybe it's worth doing so at home in your warm hangar next time you already have a few things apart!
Second finding. The third and smaller o-ring on the center of the fuel selector shaft (M83248/1-011) had damage in two spots, which was being caused by burs within the valve itself. Over time, these burs (higher rough, sharp to the touch inconsistencies in the countersunk start to the fuel channels - spots are hard to see in my photo but I drew lines to the area I'm talking about) had chewed away the center o-ring (o-ring damage easily seen in the other attached photo), which was what was allowing fuel to sneak by in the off position. Each of the three passageways were a little rough, one more than the other. It's almost as if the valve is made in halves, and then pressed together. The sharp areas are right where the two halves would come together and slightly visible to the eye, if that is how they manufacture. We used crocus cloth (sp?) to finely mellow out these rough spots, so time will tell if we honed enough. For now though, off truely means off! Pretty frustrating considering the cost of fuel selector valves, and that they should be absolutely perfect if you're shelling out hundreds of dollars for one though.
Did want to mention one or two things we found, in regards to the Allen valve listed above (82829/6S1008 ). Last year during my annual, with the gascolator apart (standard Piper/Univair/not a Steve's)/checking the screen, we found that the off position didn't stop the flow of fuel entirely. Mostly, but not all the way. There was a steady, somewhat fast dribble that continued. We didn't investigate further as it was not entirely alarming, and I'm always on both anyhow.. Plus, full fuel in the tanks and nowhere to offload solidified the decision not to investigate further. I kept it on my squawk list though, and here recently during this years annual we decided to investigate. And I am so glad we did.
First finding. On the edge of life and cracking, MS29513-114 o-rings. These are the (2) 5/8" diameter ones on each end of the fuel selector shaft. I believe it would not have been long before I started having a fuel seep/leak around the selector valve, which if one totally tore and cracked in the middle of nowhere, would be an absolute PITA. Especially when you think it's a damn $0.50 part that would be stranding you. If you haven't ever changed these, maybe it's worth doing so at home in your warm hangar next time you already have a few things apart!
Second finding. The third and smaller o-ring on the center of the fuel selector shaft (M83248/1-011) had damage in two spots, which was being caused by burs within the valve itself. Over time, these burs (higher rough, sharp to the touch inconsistencies in the countersunk start to the fuel channels - spots are hard to see in my photo but I drew lines to the area I'm talking about) had chewed away the center o-ring (o-ring damage easily seen in the other attached photo), which was what was allowing fuel to sneak by in the off position. Each of the three passageways were a little rough, one more than the other. It's almost as if the valve is made in halves, and then pressed together. The sharp areas are right where the two halves would come together and slightly visible to the eye, if that is how they manufacture. We used crocus cloth (sp?) to finely mellow out these rough spots, so time will tell if we honed enough. For now though, off truely means off! Pretty frustrating considering the cost of fuel selector valves, and that they should be absolutely perfect if you're shelling out hundreds of dollars for one though.
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Steve Pierce
BENEFACTOR
Graham, TX
Your fast, took me way more than 30 minutes. 
