gas cap replacement seal?

[13brv3]

Greetings,

I noticed today that the flat seal inside my fuel cap seems to have swelled, and the diameter has grown to larger than the inner diameter of the cap. There's a good chance it's not even sealing anymore. I had a spare and changed it for now, but I'd like to source some replacement seals. Sonex appears to sell the cap, but there's no mention of the seal separately. https://www.sonexaircraft.com/eshop/car ... t_id=16929

I supposed I can measure and try to find a seal, but I figured I'd ask here first in case someone has already found a solution.

Thanks,
Rusty

[kmacht]

Buy the one Pete Anson sells. It seals much better than the stock sonex one and uses a standard o ring if it ever needs to be replaced.

[13brv3]

Thanks. I emailed Peter to ask about that after I saw your message. His cap is radically different, though I can see how it could work. I wasn't sure if all Sonex always used the same caps, which was why I left a link to the one I have. I would certainly love to improve the cap, particularly since it's inside the cockpit with me.

Rusty

[OneTallShort]

There are two different style of gas caps for the Sonex A models. The original design was for a internal expanding stopper type seal. This is what Peter's improved design is to replace. The newer tanks have a screw top cap. I'm not sure if you can use Peter's cap on the newer tanks... but it is smooth on the inside.

Gregg Short
Sonex 715

[13brv3]

Peter replied that the new type cap can, and has been used on the new tanks, but the ID of the neck is a little smaller on the new tank. He can make both sizes, but he asked me to measure the ID of my tank to make sure the size will be right. I will probably order one, and also get the 90 degree check valve fitting for the vent tube on top of the tank. I think both of those items will make me feel better about what would happen if I ever end up upside down in a corn or soybean field.