On my '67 f1 longbed, the gas gauge shows 3/4 tank when full. how do I make it work properly? thanks, Dave

 

The usual reason why this occurres is:

The fuel sending unit float is made from two pieces of copper soldered together.

Solder breaks down, gas seeps in, float begins to settle towards the bottom of the tank.

Remove the sending unit, then the float, shake it. If gas is sloshing around inside it, it's time for a new float.

COAZ-9202-B .. Fuel Sending Unit Float / Available from Ford.

Applications: ALL 1957/79 FoMoCo Passenger Cars/Trucks, 1961/79 Econolines and 1966/79 Bronco's.

 

I have had two trucks that the guage was the problem. Check the ohms at the guage to see if it is reading correctly.

 

Thanks guys, guess im checking ohms than the floats tonight. Itll be nice just to get it fixed. shes a workin progress.

 

Keep me updated! I have the same problem!

 

well its not a tank float in my case, just yanked it out and set it in a bowl of gas, spun it every which way and didnt see a bubble or get any in the float.

 

My bet was the gauge.

 

what gauge did you replace it with. what ohms for full and empty?

 

Im going to breakdown and pick this up from autozone for $20. Equus/2 in. 73 Ohm empty / 10 Ohm full Back-Lit 90 degree sweep fuel level gauge for Ford and Chrysler

 

You can go to Radio Shack and pick up a 10-ohm resistor for a buck or two. Lift the wire to the tank, hook up the wire to the resistor and ground the other side of the resistor. Does the gauge read full? If not, some simple arithmetic will tell you what the full-tank resistance should be.

 

simple arithmetic, I have no clue about this. The gauge only goes to 3/4 when the tank is full. Now what should I do?

 

If you get a reading of half-tank with the 10-ohm resistor, the float you are proposing has too much resistance. You need a float that has 5 ohms resistance at full.
Make the test and come on back in with what you find.

 

well ill give it a try, were can i buy 5 ohm floats if need be? You said i could find the resister at radioshack.

 

David, do you have or can you borrow an ohmmeter? Do this:
Lift the wire to your present sender with the tank full. Measure resistance to ground. To make the gauge read full scale with a full tank you need a sender with 3/4 of the resistance that you measure.

 

cougarjohn i appreciate the help. I guess im going to have to buy a new one. I went out there to check it but my digital numbers are going out. chinese junk