Fuel tank sending unit

Asked by Mar 26, 2017 at 01:02 PM about the 1972 Chevrolet Impala

Question type: Maintenance & Repair

So I just replaced my file sending unit in my 72
impala! The original sending unit has one fuel line
on it and it built in a canister. The one I bought from
the parts store that says it's an exact fit has two line
on it, I'm guessing that would be like a return line or
somthing?? I don't have anything to hook up to that
second line. After installing the unit I took my car on
a drive to see if it worked and now my gas gauge is
rocking back and fourth between a half and a
quarter over half a tank on the gauge! What could
be wrong???

10 Answers

Here's the new one


Some sending units came with a return line, depending on the carb setup the car came with, yours must have been a hi-performance option with the holley carb for it to have the single line. The lower performance models with rochester carbs came with the secondary line to allow some of the fuel pressure to return to the tank to prevent damage to the carb. So basically you have the lower performance model's fuel sending unit. If you can't find the exact one you need, you may have to rebuild your original one, a lot of time it's only a bad ground wire on them that causes them to read incorrectly.


What you want is the single line sending unit with 3/8" line. What you bought is the sending unit with 5/16" line and return line. I'd take it back and get the other one.

So if they don't have one for an impala can I get one for like a Chevelle or something because those are the only ones I see that they still sell


This place has the one you need, they even have it in stock.....https://www.carid.com/1964-chevy-impala-fuel-delivery-parts/spectra-premium-fuel-tank-sending-unit-22820849.html

1 of 1 people found this helpful.

So this same one will fit my 72 even though it's for a 1964??? I didn't know that they were interchangeable like that??


Sorry, I don't know where I got '64 from, I'll keep looking tho.


Gemale, Chevelle, Nova, Impala, all work, as long as it's a single 3/8" line unit. Summit Racing and other speed parts catalogs will have what you need.


Check this one out, its for a '72 Nova... https://www.carid.com/spectra-premium/fuel-tank-sending-unit-mpn-fg104c.html?singleid=22815525&url=15255639

Do I need to fill the gas tank up? It's a little under a half of tank in there and the needle is still moving from left to right

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