Leaking O-ring in Andair Fuel Valve

Guys,
I need some more help. My fuel valve is weeping from the left port. The O-ring is bad I am assuming. I looked at Andair's website and the 0-ring is $.80. However, I don't want to have to order one and then have it shipped across the Atlantic. Too much money. I emailed Andair but have not heard anything yet. Can somebody give an MS or AN number so I will know which one to order???

Thanks to all in advance,
Darren Kerns
RV8 N214TK

I pulled one port out of a new Andair valve just to have a look at how it was put together, and noticed that the O-ring had a small sliver hanging off of it. The edge of the housing seems to be very sharp, and I think that running a Scotchbrite pad around the opening would be a good idea before installing the new, and heavily-greased O-ring. Anyway, I think I'm sticking with the stock Van's valve- fewer potential leak areas.

Darren Kerns said:

Guys,
I need some more help. My fuel valve is weeping from the left port. The O-ring is bad I am assuming. I looked at Andair's website and the 0-ring is $.80. However, I don't want to have to order one and then have it shipped across the Atlantic. Too much money. I emailed Andair but have not heard anything yet. Can somebody give an MS or AN number so I will know which one to order???

Thanks to all in advance,
Darren Kerns
RV8 N214TK

Click to expand...

If you can determine an ID & OD of the groove (assuming face seal) and an approximate cross section thickness of the o-ring you should be able to look it up in Parker's o-ring handbook. Download here: http://www.parker.com/ead/cm2.asp?cmid=3903&
As pointed out, if the groove is sharp-edged be careful during assembly, or knock the edge down a little.

I had exactly the same problem with my Andair bulkhead fuel filter...except that it was also my problem as after I'd cleaned it, I reassembled and tightened without silicone o-ring lube. Tore it into 3 pieces immediately. First of all, when re-assembling, do use o-ring lube. Secondly, if you can find the ID/OD and thickness, choose your material (viton), then McMaster-Carr and O-rings-r-us (or similar) will have what you want in stock. I bought a hundred years supply of these o-rings plus those for the brakes at the same time.

Allan

Less fluid leaks...

Also, remember that O rings need special handling when assembling. Inspect the new O-ring for nicks, cuts, modling 'flash', discard if not perfect. All dirt and burrs removed from mating surfaces, and (with relatively clean hands) liberally grease the O ring before installation with either DC-4 silicone grease, or vaseline. Applies to water lines, fuel lines, oil lines, 5605 lines, Skydrol lines. Not oxygen, not vacuum.

Art in Asheville
N666AT RV-8 Fastback
First flight in a few days.

Darren Kerns said:

Guys,
I need some more help. My fuel valve is weeping from the left port. The O-ring is bad I am assuming. I looked at Andair's website and the 0-ring is $.80. However, I don't want to have to order one and then have it shipped across the Atlantic. Too much money. I emailed Andair but have not heard anything yet. Can somebody give an MS or AN number so I will know which one to order???

Thanks to all in advance,
Darren Kerns
RV8 N214TK

Click to expand...

It is possible to damage the Andair port O-rings by over tightening the fitting. Andair advises that these fittings are light snug only and held with lockwire. I suspect many builders are using way too much torque.

Andair Metric O-ring size

I realize this is an old thread, but I did a search and couldn't find the size of the Andair fuel valve port o-rings. These o-rings are easily damaged by the sharp edge of the port flange. Andair wants ?0.92 ea plus shipping from England. I know they are metric size Viton V75 o-rings and easily available from McMaster-Carr, but I can't find the size. Andair lists these as p/n ORO25x10-VIT75. Does anyone know the size?