Princeton capacitive fuel probes

[gammaxy]

Hopefully the paste works. Sometimes the leak isn't the plug, but the actual fitting.

Since that plug is unused in my plane and it was a pretty slow leak around the fitting, I recently created a patch out of HDPE sheet, hollowed out a pocket to clear the plug, and glued it directly over the fitting. I also patched the top sight gauge fitting which was also leaking. Since almost nothing bonds well to HDPE, you have to be careful selecting a glue. The Loctite Plastics Bonding System http://www.loctiteproducts.com/p/sg_plstc/overview/Loctite-Plastics-Bonding-System.htm is available locally at Lowe's and seems to work great. If you try it, I recommend testing it on scrap HDPE first. There's really no reason that the patch needs to be HDPE except the adhesive didn't stick well to aluminum or nylon, but it sticks extremely well to HDPE. I was cautious and drained the tank and let it dry for a day before applying the patch and waited a day after patching before adding fuel.



My plane has been sitting for a month with close to a full tank with this patch and there has been zero leak. I'm hoping none of the fittings I'm actually using spring a leak since this technique will not work on them and instead I might need to install the "oops fitting".

[WaiexN143NM]

Hi to All, SonexEZ, and Chris,
Interesting , we had trouble with the lower rt hand sump fitting leaking also. It was not being used. At first we tried Teflon paste and tighten the hex plug , but still leaking. We noticed a smell of avgas gas in the plane, put down a white piece of paper towel , and the next morning noticed a small blue stain. It was the fitting molded into the tank that was leaking. We made a patch of two aluminum washers , one orange baffling material washer, and a nylon hex head plug from ace hardware, plus the locktite glue for poly E. Sanded the outside of tank , applied glue and screwed in the washer assembly. Let sit for a day. Gassed up and no leaks now for a year. I have a tank for a second Waiex that is half built, the oops fittings are much, much easier to install with the tank out of the aircraft. There is a lot of material to be removed from the plastic nub holding in the fitting. Needed different Dremel tools , files, sandpaper etc. a good vacuuming and flush out required. Sonex did good in switching the tanks to molded fitting free and using oops fittings as standard. I think if we get a leak in a fitting that we are using, I'd pull the old tank, and install the new style tank w ops fitting.

WaiexN143NM
Michael Radtke

[SonexEZ]

now i cant get it to read the correct amount again and it has a small seep somewhere

[WaiexN143NM]

Hi guy,
Wow you have a lot of fixing on that plane. The Princeton fuel probes can easily corrode , maybe someone using auto fuel with ethanol? A few people learned the hard way. My suggestion would be to buy a belite unit and gauge. Save yourself any more grief. How's your sun shade and vents doing?

WaiexN143NM
Michael Radtke

[SonexEZ]

I haven't even tried to set mine yet. It just reads 100% full all the time. I have added a few litres of premium unleaded just for initial starts. This wouldn't kill it would it?

Did you calibrate it i did mine yesterday its pretty easy but of corse you will need 16 gallons of fuel to do this

Now my unit is reading 20.1 gallons at 7 gallons in the tank has to be a bad prob eis is all set correctly according to EIS helping me set it up
I am going to order a new fuel sensor what dose everyone used on the threds to seal it ?

[tljones42]

[quote] Wow you have a lot of fixing on that plane. The Princeton fuel probes can easily corrode , maybe someone using auto fuel with ethanol? A few people learned the hard way. My suggestion would be to buy a belite unit and gauge. Save yourself any more grief. How's your sun shade and vents doing?

WaiexN143NM
Michael Radtke [quote]

Michael,
Sounds like you're happy with the Belite unit. Are you using 100LL or auto gas (no ethanol). Do you have any experience with how it functions if you switch types or mix them?

Tom Jones
ONEX #133

[SonexEZ]

I haven't even tried to set mine yet. It just reads 100% full all the time. I have added a few litres of premium unleaded just for initial starts. This wouldn't kill it would it?

No I dont think 98 octane will bother it. I use 98 octane when I can, which is most of the time, and Avgas only when I have to. The different fuels dont affect my fuel level readings. Tip, when you calibrate the gauge, get a long stick and calibrate a dipstick at the same time. I keep my dipstick behind the seat.

If you have a taildragger, sit the tail on the ground for the stick calibration. Will obviously need the tail up in flying attitude for the gauge calibration.

Steve
Sonex 892
VH-ZSX

i have the trigear