1966 Fuel Tank Sending Unit

[Donald H.]

I'm looking to either buy a new sending unit or have mine restored. I've searched the forum and most of the recommendations is that there are not really and good/reliable reproductions. Has this changed recently? Is there a reproduction that is reliable?

I also read that John Wolf and Co is the best at restoring them. Mine is an original, but has a lot of pitting on the outside of the base. It is not rusted through, but is pitted. The AC is readable, but almost gone.

It is still better to have this one restored?

Thanks,
Don

[Jim S.]

Re: 1966 Fuel Tank Sending Unit

If you can find an original non working unit to use as a core, the interior portion can be repaired using parts from a new unit.

[Harry S.]

Re: 1966 Fuel Tank Sending Unit

An FYI from an archived thread from Joe Lucia.

There were actually FOUR different part numbers, including two that were SERVICE-only:

1963----GM #5642797 (SERVICE only)

1963-64-GM #6425113 (PRODUCTION and SERVICE)

1965-67-GM #6425827 (PRODUCTION and SERVICE) (also 63-64 SERVICE)

1963-67-GM #6428065 (SERVICE only)

[Gary B.]

Re: 1966 Fuel Tank Sending Unit

Don,

I concur with Jim's suggestion, which is exactly what I did for my '66. Start looking on e-bay and elsewhere for a good, used core and send that to John Wolf for restoration. To the best of my knowledge there is no perfect repro that will both work and be cosmetically correct to the chassis judges. A restored original is the only way to guarantee no deducts.

Gary

[Jim S.]

Re: 1966 Fuel Tank Sending Unit

An FYI from an archived thread from Joe Lucia.

There were actually FOUR different part numbers, including two that were SERVICE-only:

1963----GM #5642797 (SERVICE only)

1963-64-GM #6425113 (PRODUCTION and SERVICE)

1965-67-GM #6425827 (PRODUCTION and SERVICE) (also 63-64 SERVICE)

1963-67-GM #6428065 (SERVICE only)

[Donald H.]

Re: 1966 Fuel Tank Sending Unit

Don,

I concur with Jim's suggestion, which is exactly what I did for my '66. Start looking on e-bay and elsewhere for a good, used core and send that to John Wolf for restoration. To the best of my knowledge there is no perfect repro that will both work and be cosmetically correct to the chassis judges. A restored original is the only way to guarantee no deducts.

Gary

The one I removed from my tank is an AC unit. I was not sure how good it needs to be for restoration. I sent an email to John Wolf this AM.

Thanks,

Don

[Harry S.]

Re: 1966 Fuel Tank Sending Unit

Sorry, can't help with that.

[Jim S.]

Re: 1966 Fuel Tank Sending Unit

The one I removed from my tank is an AC unit. I was not sure how good it needs to be for restoration. I sent an email to John Wolf this AM.

Thanks,

Don

[Wayne W.]

Re: 1966 Fuel Tank Sending Unit

Some of the later repros with the modern type rheostat work fine and are reliable. The older off shore ones are weak at the electrical connections and leak there. Rik`s carries the better repro. I am sure others do to.

[Donald H.]

Re: 1966 Fuel Tank Sending Unit

I have been checking out my sending unit. I found the problem. The flat wire (I think it is brass) is broken. Does anyone know why one wire is thin brass flat wire the the other is stranded insulated 18 gauge wire? And, if the length is critical?

If the length is not critical, I think I can overlap the break slightly and solder the piece.

The rheostat work fine - reads 5 ohms at bottom and 94 ohms at top.

Thanks,
Don

[Wayne W.]

Re: 1966 Fuel Tank Sending Unit

One wire supplies 12V and the other is a tap from the rheostat. There is no reason that length would be a factor in that short of a run.

[Larry M.]

Re: 1966 Fuel Tank Sending Unit

Agree with Wayne.

The break was likely caused by fatigue over the years at a "flex point". I would try and find a piece of thin copper or brass to add a bit of extra length and give you some room for overlap of the flat wire ends. Checkout brass or copper shim stock a get a piece the same thickness as original. Cut to fit.

FWIW

Larry

[Donald H.]

Re: 1966 Fuel Tank Sending Unit

Thanks,

I need to decide if I want to fix it. I have been trying to contact John Wolf. I would like to fix it myself, but I would also like to have it re-plated. I can do zinc at home, but as I understand these were tin plated. Also I have read at least one thread that it should NOT be plated with anything but tin.

Don

[Donald H.]

Re: 1966 Fuel Tank Sending Unit

I sent my sending unit to John Wolf for restoration. Pictures below are after restoration. They do a very good job of cleaning up and re-plating. The AC MADE IN USA was not even visible when I sent it to them. I though the corrosion had actually eaten it away, but it came out great.

As you can see, use of a flat brass wire on the original must not have been critical since they replaced it with what looks like a standard 14 gauge insulated wire. I've checked the resistance at the terminals and on the low end it is close to zero on the high end it is 84-95 ohms.

They removed the original strainer and returned it loose in the box. I don't know how it was attached and exactly where. I didn't get a good picture before I sent it.

Does anyone have a good clear picture of a side view that show the strainer in relation to the rest of the unit? The pickup tube looks like it would be about 1/4" from the bottom of the tank, so I assume the strainer would go up pretty far on the tube.

Also, is the strainer just slipped up on the tube for a somewhat friction fit? There are no indications on the tube of where or how the strainer was attached.

[Donald H.]

Re: 1966 Fuel Tank Sending Unit

Found a couple of good side view pictures, so I don't need any pictures. But still asking for how was the strainer attached?

Thanks,

Don