Gas Gauge Always on Full...Until Empty!

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Jan 14, 2008 | 07:41 PM

The Reverend Floater

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Gas Gauge Always on Full...Until Empty!

Okay detectives, I've got one for you: My gas guage is always reading full until it gets down to approximately 3 gallons. At this point it starts wavering back and forth until it finally rests on empty at about 1 gallon. What's the problem? The gauges are all new and are all OEM, which solved the tach and temp gauge failure problems but didn't effect the gas gauge.

Keep in mind I'm a relatively new mechanic so talk to me like you're explaining this stuff to your girl friend, minus the *** pats and what not. Thanks.

Jan 14, 2008 | 07:44 PM

fordguy300

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From: THEHAUTE

have the same problem in the 87 i have i havnt changed gauges b/c they all work cept gas i have been told theres a spring on the float that controls it also that i need to change my sending unit hope this helps someone correct if im wrong

Jan 14, 2008 | 07:47 PM

95F350XL

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From: Belle Mead NJ

I was going to say that your float might be sticking for some reason. It might also be the sending unit in the tank.

Jan 14, 2008 | 07:56 PM

The Reverend Floater

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Okay, so by both accounts, it's probably a tank problem which was my inclination to begin with--I'm guessing a sticky float or the like. I've checked under the truck and it looks like the tank is pretty easy to get at...any tricks? How do you keep from spilling gas already? Anything to watch out for? Gaskets that'll need replacing, special tools, etc.?

Jan 14, 2008 | 08:03 PM

95F350XL

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From: Belle Mead NJ

Umm run the truck till it runs out of gas, if your going to have the tank down, Id prob change the pump and such so you dont have to redo later, unless you have changed it already. I dont think there are any gaskets, maybe just where everything bolts into the tank.

Jan 14, 2008 | 08:03 PM

fordguy300

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From: THEHAUTE

i dont know what you will need but when i take mine off im liftn the bed off which is suposivly easy plus mine is the back tank which has a rese hitch under it anyways once you lift off hte bed you can just take off the top section of the tank

Jan 14, 2008 | 08:15 PM

Conanski

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From: Ottawa, Ontario

This is a common problem with these float style sending units, one of mine does the same thing. The problem is the potentiometer, for the electronic types out there, it's just a variable resistor with an arm and float attached to the center tap that moves up and down with with the fuel level. This simple assembly is bolted to the outside of the fuel pump resovoir and is easily changed when you pull the whole thing out.