hey guys I just replace my entire fuel system from carb to fuel pump, filter, fuel lines, gas tank (19 gal after axel) and my fuel sending unit. Well I put in 8 gallons of gas in the new tank and my gauge only shows almost a 1/4 tank so that's got to be way off if I only have a 19 gal tank. was I suppose to bend the float rod in the tank to get it to go to its lowest point?

 

COAZ-9202-B .. Fuel Sending Unit Float is made from two pieces of brass soldered together.

Solder breaks down, gas seeps in, float slowly settles towards the bottom of the tank.

Float available from Ford, same: 1957/79 Passenger Cars/Trucks, 1961/79 Econolines & 1966/79 Bronco's.

Carpenter sells a one piece brass float that'll never leak for about 5 bucks.

 

like I said in the post every thing is NEW I don't have a bad float.

 

'may need to bend the float arm to get it to read more accurately.

I had a 76 whose indicated fuel level dropped really fast on the first half of the tank and then markedly slowed down when indicated to be half full. I finally got around to changing the sender and opened it up to see what was going on. The windings on which the arm "wipes" agains were spaced really far apart. The windings on lower half of were tightly bunched to gether and summarily, read "slower".

I think you'll go bananas trying to get it to read accurately. I say figure out your mileage per tank and how much fuel it takes to fill up based on the indicated fuel level... it's just one of those quirks with old technology.

Oh, just because it's "new" doesn't mean it is gonna work or work accurately.

 

Thanks silver. Yeah I think if I add more gas it will go up more substantially. In a previous post I posted that my carburetor had a bunch of junk in it then my fuel pump went out so I went out and replaced everything from the gas tank to the carburetor. This is the first time I'm able to see my fuel level because when I bought the truck it never worked. so I guess when I'm between empty and a quarter tank I know I have 8 gallons.

 

on another note. NumberDummy, did ford ever make a dash cluster that had a trip odometer that could be reset for the 73-77 trucks?

Sure would be neat to have.

 

This is likely an electrical problem, not a mechanical problem. You should not have to do any adjustment to standard-issue 19-gallon sending units. Verify the ground at the sending unit, as this is responsible for at least 50% of fuel level issues, and about 95% of them if the sending unit is new. If running a jumper wire from the sending unit ground point to bed sheetmetal helps the problem, then this is a ground issue. Stray impedance along the frame reduces the current through the fuel gauge, which gives a false LOW reading. I had to sand the ground point on the crossmember to get mine to work again.

However, just because your float is new does NOT mean the float has not already filled with gas and sank! The soldered brass floats that come with new sending units are JUNK. I've had them come bad out of the box on TWO separate occasions. Disconnect the sending unit and verify its resistance; if it reads 70 ohms with much gas in the tank, you can bet the sending unit is riding the bottom of the tank. I do NOT use the brass floats that come with the sending unit; I upgrade to the Stewart-Warner type that Dennis Carpenter sells. I've had a couple of them show up with holes in them, but as long as they start out fine, they're not going to break down over time like a cheap soldered float would.

 

That's pretty "accurate" for these rigs.

 

I don’t know of any gas gauge that was that accurate on older vehicles. You just need to track your mileage and know when you are going to get in trouble. Fortunately I have two tanks and always keep gas in the spare tank, (Kinda like having a reserve like on motorcycles)