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Apr 26th, 2026 | | AD Chevy Trucks  Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
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| | | | Joined: Nov 2005 Posts: 206 'Bolter | | 'Bolter Joined: Nov 2005 Posts: 206 | The new 58 apache at our house has an issue with fuel gauge. It reads 1/4 tank when the tank is full and needle disappears past empty when half tank left. Yes I cleaned terminals on gauge and connectors and the ground wire on fast and terminal and where it grounds to body. Should I just buy new sending unit or is there an adjustment I can make on the current sending unit. Yes the whole truck is original or after market like original parts. Thank you | | | | | Joined: Oct 2021 Posts: 6,792 'Bolter | | 'Bolter Joined: Oct 2021 Posts: 6,792 | Make sure the float and arm isn't rubbing the side of the tank or getting stuck on a baffle.
Measure the depth of your tank and make sure it's the same as the full range of travel for the float. Bend it or lengthen it as required and see if it records correctly.
1950 Chevrolet 3100 (Ol' Roy)
1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)
| | | | | Joined: Nov 2005 Posts: 206 'Bolter | | 'Bolter Joined: Nov 2005 Posts: 206 | | | | | | Joined: Feb 2019 Posts: 4,479 AD Addict & Tinkerer | | AD Addict & Tinkerer Joined: Feb 2019 Posts: 4,479 | What Otto said is a solid suggestion. If you need further help, there is a Tech Tip that covers troubleshooting the gas gauge, wiring and the sending unit. I would suggest testing before you replace anything. Here is a link.
Last edited by Phak1; 10/29/2025 11:41 PM. Reason: Added info
Phil Moderator, The Engine Shop, Interiors and Project Journals1952 Chevrolet 3100, Three on the Tree, 4:11 torque tube Updated to: ‘59 235 w/hydraulic lifters, 12v w/alternator, HEI, PCV and Power front Disc BrakesProject JournalsStovebolt Gallery Forum | | | | | Joined: Oct 2019 Posts: 113 59 Apache 3100 | | 59 Apache 3100 Joined: Oct 2019 Posts: 113 | Make sure the float doesn't have a pinhole & has fuel inside. My brass one failed (new) & I replaced it with a plastic one (also failed) .
I got an improved float off e-bay & it been good for 18 months. Made of polyurethane & is buoyant like a cork.
The seller was "angels stuff now", (I'm not affiliated with the buyer). Good luck
1959 3100, original 235/3 on the tree w/overdrive. Carter YF 2100S carb, 205/75/15 w/front sway bar
| | | | | Joined: Mar 2007 Posts: 3,390 Crusty Old Sarge | | Crusty Old Sarge Joined: Mar 2007 Posts: 3,390 | I can attest to to Phak1's troubleshooting PDF. I have been chasing electrical Germlins since adding a new wiring harness.
I had been through all basic tests, wiring, power, grounds and sending unit. Turns out the my gauge had let the Magic Smoke out. His gauge helped a good bit.
~ Craig 1958 Viking 4400"The Book of Thor"Read the story in the DITY1960 Chevrolet C10"A Family Heirloom"Follow the story in the DITY Gallery'59 Apache 31, 327 V8 (0.030 over), Muncie M20 4 Speed, GM 10 Bolt Rear... long term project (30 years and counting) If you don't like driving yourTruck, you won't drive yourTruck..| Living life in the SLOW lane | | | | | Joined: Nov 2005 Posts: 206 'Bolter | | 'Bolter Joined: Nov 2005 Posts: 206 | | | | | | Joined: Nov 2005 Posts: 206 'Bolter | | 'Bolter Joined: Nov 2005 Posts: 206 | I’ll check it out if I can navigate to it. Thank you sir | | | | | Joined: Feb 2019 Posts: 4,479 AD Addict & Tinkerer | | AD Addict & Tinkerer Joined: Feb 2019 Posts: 4,479 | The link was in my post above, but here it is again. Here is a link.
Phil Moderator, The Engine Shop, Interiors and Project Journals1952 Chevrolet 3100, Three on the Tree, 4:11 torque tube Updated to: ‘59 235 w/hydraulic lifters, 12v w/alternator, HEI, PCV and Power front Disc BrakesProject JournalsStovebolt Gallery Forum | | |
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