Fuel level sender - a substitute

[yvesmontreal]

I'm starting the revival of a 1969 Elan that hasn't been run in 10 years.

I first drained the fuel tank of the remaining gas. Not so bad, the owner had siphoned out most of it. While the tank was out, I checked the level sender - the PO had warned me that it stopped working when he got the tank sealed in and out. It quickly became clear why - the idiots sealed the tank with the sender in place!

Getting the screws off was a nightmare- I had to gently chisel off the coating around the screws to attack them with a vise grip. No sparks, please.

The resistor got coated along with the inside of the tank. The wiper probably got stuck on the resistor at the same time, resulting in a broken resistor when it started moving around.

Dead.

New senders are available from UK at $100+ and at least a week away. The Smiths part number TB1114-023 does not seem to have been used on any other car. I need the tank back in the car ASAP.

Hunting the net for similar senders produced images of Triumph TR6 senders: very similar but with a longer float arm.

A quick visit at the local British parts supplier confirmed that indeed it is the same sender (1114-20) with a different arm. $50 later it was mine.

[yvesmontreal]

Before modifying anything, I checked the sender resistance: 230 ohms empty, going down as level increases. As required. Once connected to the car, the sender did modulate the fuel gage reading.

First step was to redrill the flange. I considered using it as is, but I feared leaving the mechanism cocked sideways would put a strain on the wiper and resistor. A stepped drill made nice clean holes.

Use of gasket to mark the new hole locations.

Next step was to bend the lever to the proper shape. The rod is a bit springy but quite ductile. Straightening the bends was rather easy; making the loop to hold the float was trickier. I wound the end of the rod around a 11 mm socket to shape the loop; the ID has to be 22 to 23 mm to hold the float tightly. Some trial and error here, especially if your first try makes the loop too large.

Finished product.

In less than an hour, the modified sender was ready to install.

Check - minimum level.

Check - maximum level.

Sender installed.

[sveris]

Nice work on the conversion, and good cross reference info for everyone to have. Do you know if the TR6s all used the same sending unit, or did it vary by model year?

Steve in Ohio

[billwill]

You will need to check that you don't get fuel leakage from those redundant holes.

You might need something like a tinfoil gasket between the cork gasket and the sender rim.

[el-saturn]

saving 50 dollahs while spending 400 on labour seems to be out of proportion - 2 hrs cost 400$ in these parts SOOOOOOO i do most everything myself saving 5000 dollahs a year - just put my engine back in after: new release bearing (ruined afer 1500mls AGAIN) , new front plate (alternator eye broke off!!) new water pump etc., new head gasket (cometic), sealed sump and timing case: at least 30hrs = 6500$ - lots of cussing and very little beer! didn?t replace cover gasket yet, so it?s crying - old man with a f.....d spine sandy 36/4982 - ready for friedrichshafen this weekend!!! hurrah!!!

[yvesmontreal]

sveris - Moss lists the same sender for all TR6s and 250s, 1968-1976.

billwill - I was thinking of that. But the other side of the gasket is solid steel.

el-saturn - Paying for labor to do this would not make sense. But to me playing with old cars is a hobby; if the hobby was just hunting the countryside to find competent mechanics and then throw money at every problem, I would have given up a long time ago. Main point, I did not want to wait two weeks to mail order a new sender before putting the tank back in the car. And what if new Elan senders are back ordered? I hate playing with fuel and did not want to do it twice.

[billwill]

Yves,

Sealing the tank sender has been extensively discussed before.

lotus-carbs-f40/tank-sender-sealing-t30071.html?hilit=rivets

Alex Black came up with the technique of using 'blind' rivenuts to stop seepage along the threads of the bolts. This might not apply to you, as the sealing that caused your sender problem may have prevented such seepage.

I haven't done mine yet and do tend to get a smell of petrol in the boot.

[gjz30075]

Have you thought about (I know, too late now, but...) using the original holes in the new sender and simply
twisting the rod to level out the float? I don't suspect that'll be a problem, with the float simply riding up
and down on fluid.