Author Topic: Fuel Tanker Sender  (Read 2373 times)

Offline AlabamaLiving

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Fuel Tanker Sender
« on: December 30, 2019, 01:46:43 PM »
I got a 1979 K20 Custom Deluxe. I put dual tanks in the fuel system since I have a dual tank bed. I got the selector valve and selector switch working properly. My difficulty is that the fuel gauge is not working.

Troubleshooting revealed that the senders are grounded out. This cause the fuel gauge to remain on empty. My second test was disconnecting the sender gauge line, and the gauge went to full.

These are new senders that read 0-90 ohms when I bench tested them. I removed one sender from the tank to check it. It is grounded, but at full level it reads correctly at about 33 ohms.

I read that many have had problems with aftermarket senders. First, am I missing anything? Second, please recommend a quality fuel tank sender that is closer to OEM standard. Thanks.

Offline AlabamaLiving

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Re: Fuel Tanker Sender
« Reply #1 on: December 31, 2019, 09:05:16 AM »
I ran across Spectra Premium Fuel Tank Sending Unit. This looks like higher quality unit especially the level sensor. It about 30% more cost. Has anyone used this product?

Offline MIKE S

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Re: Fuel Tanker Sender
« Reply #2 on: December 31, 2019, 12:56:10 PM »
I have spectra on my 78 and on both tanks on my 87. Both work fine. I did have a problem on my left tank on my 87 after install. It ran out of fuel at a quarter tank. Dropped tank and found float arm at bottom of tank. Put it back on sending unit and is has been good since. Only thing I can think of is the arm was not fully seated in the retainer before I put it in tank. I don't particularly like the way it is retained but it hasn't come back off.

Offline AlabamaLiving

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Re: Fuel Tanker Sender
« Reply #3 on: December 31, 2019, 01:05:13 PM »
Thanks for the info. I think you sold me on it. You could have been a salesman! I'll check the floats before installing.

Offline bd

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Re: Fuel Tanker Sender
« Reply #4 on: December 31, 2019, 03:06:02 PM »
For an OEM replacement, you can use an ACDelco FLS1098.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline MIKE S

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Re: Fuel Tanker Sender
« Reply #5 on: December 31, 2019, 03:08:26 PM »
I would use an oem sender seal and possibly the lock ring. If I remember I had a hard time on the 78. I used an aftermarket tank and had a real hard time keeping the seal from seating in the grove and would eventually shrink some and leak fumes. The oem seal has metal inside to make it stiffer and a believe it has some lips on it to keep it from moving. Also the ring is a little chinsey and tends not to work as well as a used oem. The seal number is GM 22515965. The cam ring number is 25124032. They are both still readily available. 

Offline MIKE S

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Re: Fuel Tanker Sender
« Reply #6 on: December 31, 2019, 03:17:15 PM »
I just checked the GM locator and FLS1098 is discontinued. Gm dealers have the ability to buy parts from a place called vintage parts that still has some stock of this number but is kind of pricey. $239.13 list.     

Offline bd

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Re: Fuel Tanker Sender
« Reply #7 on: December 31, 2019, 03:33:31 PM »
FLS1098 still comes up on Amazon and eBay at about $140.  Kinda proud aren't they?
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline AlabamaLiving

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Re: Fuel Tanker Sender
« Reply #8 on: December 31, 2019, 03:50:21 PM »
Thanks bd and Mike for your insights. Ebay was the same price too. GM sender looks like it has a good level sensor, but I'll stick with Spectra. I got a plan and now I got to get it to work.

Offline AlabamaLiving

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Re: Fuel Tanker Sender
« Reply #9 on: December 31, 2019, 04:00:12 PM »
The GM seal is a higher quality. Thanks Mike.

Offline MIKE S

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Re: Fuel Tanker Sender
« Reply #10 on: December 31, 2019, 05:01:45 PM »
I just looked at the seal I have at home and it does have locating ears on it.

Offline AlabamaLiving

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Re: Fuel Tanker Sender
« Reply #11 on: January 09, 2020, 04:47:25 PM »
I got the new Spectra sending units and tank seals that Mike mentioned. Bench tested and tested on the truck manually. All good. Good quality sending unit (everything is installed). The tank seals by GM are much better also and with the ears they keep the seal centered in the tank opening.

Thank you all for your assistance! I have more work to do...moving up. I finally drove it out of the garage after 3 years. The wife's happier.