Fuel Sending units

[Doogie]

Seems the suppliers (well, two that i've talked to) are out of fuel sending units, and I need a new one.

I've been told a replacement is in the works, but guestimated availability is summer. The one I have was sitting in fuel for the last 25 years, gumming it up pretty well.

Is there anything I can soak my old one in possibly to loosen the float, or can I even take it apart to clean everything (I didn't look at it closely, I just tossed it aside assuming I could get a new one, and it's not with me at the moment)

Maybe mineral spirits or something? Anyone did this before or should I just put it back in (to cover the hole) and wait for a replacement to arrive?

[dmc6960]

If the coil is not malformed or damaged, and the unit truly is just "gummed up", then minieral spirits would work well to loosen and break it up. Acetone would work best but I'm not 100% on its compatibility with the components of the sender. Be aware, do not force the float to move once the tarnish starts loosening, or you'll mess up the coil inside.

Soak it for a few days.

[Doogie]

Thanks Jim. I'll get the unit Monday and drop it in some Mineral Spirits for a few days. Might as well see what happens! Thanks,

Doogie

[Bitsyncmaster]

You have nothing to loose by soaking it. I would try MEK (sold at Lowes).

[DMC5180]

MEK is some NASTY stuff.

I'd stick with Acetone or get a Fuel System cleaner like Berrimans B-12 chem-tool (it's primarily Acetone with a few other ingredients) Available at Wal-Mart and most Auto Parts stores. It will not hurt anything in the original sender.

[Bitsyncmaster]

MEK is some NASTY stuff.

It's the most powerful solvent you can buy. Definitely work outside with it.

[DMC5180]

It's the most powerful solvent you can buy. Definitely work outside with it.

Yup and also the most hazardous to your health. Proper PPE should used. Which is why I suggest sticking with Berrimans or an equivalent.

[Doogie]

Thanks guys,,,.. I have it sitting in some acetone, about 12 hours on so far. The acetone is sloowwly turning brownish, and I periodically go and 'agitate it'. (It's sitting outside in a jar). I'll leave it soak and agitate it as necessary. I was talking locally with my Delorean expert, and after a few fruitless phone calls around to confirm no had sending units, we conjured up another 4 old used/gummed up but not discarded units to give a try on also. I got a whole gallon of acetone, so maybe 1 or 2 of them might be salvageable.

If not, I guess I'll take the cleanest one and put it in the tank (to cover the hole) and drive around until replacements are available.

(or until someone reads this thread and decides to put the last NOS one they have on ebay starting at $500!)

:devil:

[Bitsyncmaster]

If it still does not clean, try other solvents. Would be good to know what works best. Your doing good just keeping it outside. Maybe set it in the sun to warm it up.

[DMC5180]

Thanks guys,,,.. I have it sitting in some acetone, about 12 hours on so far. The acetone is sloowwly turning brownish, and I periodically go and 'agitate it'. (It's sitting outside in a jar). I'll leave it soak and agitate it as necessary. I was talking locally with my Delorean expert, and after a few fruitless phone calls around to confirm no had sending units, we conjured up another 4 old used/gummed up but not discarded units to give a try on also. I got a whole gallon of acetone, so maybe 1 or 2 of them might be salvageable.

If not, I guess I'll take the cleanest one and put it in the tank (to cover the hole) and drive around until replacements are available.

(or until someone reads this thread and decides to put the last NOS one they have on ebay starting at $500!)

:devil:

Did you carefully remove the bottom of he unit. The little brass nut is all that holds it all together. About the only good way to clean it is disassembled. Just be care with fine coiled wire. Try not to disturb it to much. Perhaps use a soft paintbrush to dislodge any heavy varnish. Btw: some photos would good, just so we can see what you are dealing with.

Here is what it looks like disassembled.

8261 8260 8262 8263 8264 8266 8268

[David T]

Acetone will work, you have to be patient. MEK is also good but as pointed out, even more dangerous (Acetone is already very dangerous!). Same for Lacquer thinner. At that point you might just as well use gasoline. You have to be very careful with all of the thin wires in the OE sending unit. I was never happy with the way a "repaired" sending unit worked. Even when they were new they didn't work all that good! I suppose a "repaired" one is better than nothing though. Cross-check your fuel with the trip odometer to keep from running out and it can't hurt to have a small gas can too. If you keep looking maybe you can find a TankZilla.
David Teitelbaum

[dvonk]

Here is what it looks like disassembled.

thanks for the photos, i love taking things apart to see how they work.

it appears that the fine, coiled wire on the shaft creates variable resistance based on the position of the float... rather similar to a rheostat. is this correct?

[stevedmc]

Grady might have some since he is Houston's biggest customer. I would check with him and if he doesn't have one call Hervey. Hervey used to repair them for about $60. He might be able to fix yours if You send it to him.

[DMC5180]

thanks for the photos, i love taking things apart to see how they work.

it appears that the fine, coiled wire on the shaft creates variable resistance based on the position of the float... rather similar to a rheostat. is this correct?

Correct. It is a resistance setup. The fine wire coils are not bonded to the column. You can slide them around but I don't recommend doing that because it so fragile. In theory though you could Tune the gauge by manipulating the Coil placement. Many EARLY cars have gauges that that will only show 3/4 tank when full I'm Not sure if those could be fixed with manipulation or not. The sender in those photos is a (late 81 model)

[dvonk]

awesome, thanks for the info! :smile: