Leaking fuel sample drain valve

[tedjgordon]

Hi all:

Yesterday in pre-flight, after taking a fuel sample from my right wing fuel tank, I saw a continuing dribble of fuel. I pushed in again with the sampling cup probe and still drip drip, in fact more of a minor stream. Two or three more cycles cured the drip, but I know it's only temporary. This is a repeat of a similar experience two weeks ago. So the questions are: what is the replacement for the sampling valve? Can it be replaced without draining the tank (like the Dutch Boy with his finger in the dike)?

Ted Gordon

[John Lawton]

Hey Ted,

I had something similar to this happen with a Citabria that I owned once. Turned out it was a tiny little piece of grit that somehow made it's way into the seal on the sump drain. The grit would occasionally hold the valve open just enough to let it drip. I ended up having to take the drain valve off and flush it backwards with acetone to clear it.

I doubt there's a way to rectify this without draining the tank.

Hope it helps!

Regards,

John Lawton
Whitwell, TN (TN89)
Ximango #135

[tedjgordon]

Thanks John. Chuck Cheesman tells me that this is a standard Cessna part but he doesn't know the part number. Oh well.

Best
Ted

[John Lawton]

Hey Ted,

Check Aircraft Spruce. They carry it. Quite a few things on the Ximango that aren't proprietary to Aeromot are available through ACS.

Regards,

John Lawton
Whitwell, TN (TN89)
Ximango #135

[bruceschimmel]

Ted, I wouldn't give up on clearing the grit from the valve, even if you have to remove it. what the heck...it'd be a good time to adjust the fuel gage. hope all's well. b

[Holliday Obrecht]

Hi Ted,

I had to replace one of my tank drain valves when I first got my Ximango. John is right: it is a standard part, found in the Aircraft Spruce catalog. ($20+) if I recollect right. Usually these valves have a small "o" ring that can be easily replaced, but this valve is a sealed unit, with no way to get to the "o" ring to clean and replace it. It more easily captures sand and grit and is harder to flush out by letting it run. Run the offending tank down to reduce head pressure and get a few corks handy about 1/2" OD. Get a catch can ready with more volume than you have left in the tank, just in case! Unscrew the valve, and just before the last thread, get that cork ready to push in the hole as you remove the valve. If you are fast, and the cork fits tight, you will loose only a little fuel into your catch can. Then you can eyeball the valve to order the correct one.

Hope this helps,
Holliday
SN 130

[tedjgordon]

Dear All:

Thanks for the responses. In the process, I found the part number for the replacement drain valve. It is a valve also used on Cessna's 152, 172, 180, and 185. The Cessna part number is PT# 52106-2. It is made by Manufacturing Division (sic) of Canfied Ohio (330 533 6835) which gives the part number as Model F391-72.


Best'
Ted Gordon