Quick Help, Please?

[Av8r3400]

I need to remove and rebuild a sump drain valve in one of the wing tanks on my 1050.

Can anyone tell me what size pipe thread the valve is where it screws into the bottom of the tank?

I want to get a hose fitting to drain the tank after I remove the valve.

This will require a quick changeover and a little post change clean-up I know...

[DesertFox4]

1/8" standard pipe thread Larry.
I suppose you just filled the fuel tanks too. That would be my luck.
If you had a siphon hose you can quickly drain the offending tank.

[Av8r3400]

Yup. Plumb full. 13 gallons.

PLUS-- I've been sick with the flu all week so I can't fly any of that fuel off, 'cause I'm too drugged up.

[Papa Beach]

I have a problem with both wing sumps leaking (one drop every 7 or 8 seconds). I changed the o-rings in both a month ago which helped for a few days but now back to where they were before.

Does this then mean I will have to change or rebuild the drain valves? Is this difficult? I'm mechanically challenged. There appeared to be a bit of debris in the tanks when I changed the o-rings...is it possible that may again be the problem? No debris since.

[Av8r3400]

Drain valves are $6 each at my local FBO. I have now replaced both of them.

Auto gas seems to dry out and ruin the o-rings. The rings on the valves I had were/are not regular round o-rings, but had a triangular cross section. Replacing the entire valve was cheaper than getting a replacement o-ring...

[akflyer]

These are just the curtis drain valves right? We have been using the same ones for years here without any issues running auto fuel. Is it possible that you are getting some moonshine mixed in and that is what is eating the o-ring? When they gonna figure out that moonshine os only meant for human consumption and recip engines should never be allowed to drink it!

[Papa Beach]

Thanks guys. It shouldn't be moonshine as I am using premium shell autogas and the dealer has checked with the distributor regarding alcohol content and was told no alcohol in premium fuel. In addition, it is served up in a seperate hose. But you have me thinking so will check for alcohol...just in case!

[Av8r3400]

I test for 'shine on every load and have not found any (yet).

These valves (specifically the triangular o-rings) are not meant for all the other crap that is put in auto gas either. I think that is what causes problems...

[Papa Beach]

Thanks Barry, that may prove useful to someone on this forum. Unfortunately, I have a tri-gear...and no header tank!

[Av8r3400]

Keep in mind that there is quite a bit of "unusable" fuel in the wing tanks. This is where the sediment, water and other contaminants will collect, thus the reason for having drain valves there.

I, too, thought of eliminating them until I had a conversation with a local A&P/IA who pointed this out. That's why I kept mine.

[Jerrytex]

So on these sump drains...does anyone know the o-ring sizes or seat sizes? I just filled up both tanks, and there is a drip on both sump drains. I'd like to order the parts and have them ready so when the tanks get low, I can change them out.