Fuel Level senders

[LynnR]

My Fuel level senders are not working and would like to know what other are using for senders?

[zkelley2]

Sight Gauges. They don't fail.

[JimParker256]

Sight Gauges. They don't fail.

I really like sight gauges, as well. But even though they are FAR more reliable than the old "can on a stick" float gauges, they CAN fail or provide false readings. Grumman used sight gauges in the AA-1 series, and there were numerous discussion on the Grumman forums about those sight gauges providing inaccurate readings and causing issues. Some models used a floating ball in the sight tube, and the ball could either become stuck or sink to the bottom so that it indicated incorrectly. The other fairly common issue was getting debris in the tank that could block one or both sight gauge outlets, preventing the free flow of fuel in/out the sight gauge, resulting in false readings.

The sight gauges on my current plane (RANS S-6ES) use flexible clear tubing, and the builder left them about a 1/2 inch too long, so they have a small "sag" in the middle, making it hard to read that part of the gauge. To remediate that, I plan to use "rigid transparent tube" when I replace the current tubing. It will be similar to what Batson described in post #18 of this thread. I do wish the builder had used a mesh screen "cover" (extending well beyond the fitting itself) over the upper and lower sight gauge orifices, just like the mesh used at the fuel pickup lines. That would have prevented the issues found with the Grumman AA-1 series over time. That wasn't done on my RANS, but at least the builder used fairly large diameter fittings, which makes blockage less likely.

But even with all the above, I still use a fuel flow sensor and religiously check the sight gauges against the fuel quantity remaining on the GRT EIS system, in addition to doing a "sanity check" against expected fuel consumption. Hopefully you guys won't ever have to read about me in one of those "stupid pilot ran out of gas" stories...

[AZBearhawk272]

Lynn,

How are you doing?

I have installed Stewart Warner M-385C-F. Summit Racing P/N SWW-385CF. Installation Kit SWW-366LP-F.
I installed them in the inboard tank end with the sender unit up to the top edge of the tank.
Created a backing ring of 1/8 material drilled and tapped to accept the screw threads.
Backing ring was slit into two arcs radially outwards so they can be passed through the sender hole.
You need a backing ring on the backside to clamp the end flat so it will not leak.

Had to shorten the sender arm so it would not hit the interior baffle. Easily done by removing the arm from the sender, it clips in, cutting and re-bending the 90 end.


Now the tricky part..... the backing ring has to be spiraled into the tank through the sender hole and aligned and kept in place with some thread or fishing line.
Goop up the access hole, install the sender gasket, more goop, install the sender, goop up the screws. Position and start screws. Remove thread and tighten down.

The Goop...Believe it was Locktite or Permatex Form-A-Gasket sealant. A red / blue / purple nasty sticky paste. Made specifically for fuel applications. It is not like silicone sealants.
Had to order it in from NAPA auto parts.

Good robust part, simple, no leaks.

Kevin D
#272
Phoenix AZ.

[LynnR]

Thanks Kevin. I am doing good. How about you?

[AZBearhawk272]

Lynn,

Doing good, have been out with Scott and Pat for the last week doing a bit of back country aviating.
Trying to get my perpetual project wrapped up and flying.
Are you still in Kanab?

Kevin