Fuel tank sender

[aston@ultrasw.c]

I recently installed a new fuel tank sender.

On two occasions it has stuck at about half full. Otherwise it works ok.

So if i remove it what should i look for?

[dap930]

Verify that the top of your fuel tank has not collapsed slightly in the area where the sender is installed. If this is the case, the sender can hit the rear of the tank when fully installed and tightened down which will cause the float to bind. If the tank is the problem, some people have been able to tweak the flange using a round piece of wood to bend it back. I ended up making a tapered stainless steel shim to level the tank flange out.

Also, take the sender out and reconnect it electrically. Test it with the key "on" by flipping it end for end to see if there are any issues with it moving while observing the fuel gauge.

[aston@ultrasw.c]

Verify that the top of your fuel tank has not collapsed slightly in the area where the sender is installed -

You might be right. I will check. I seem to remember crouching on the tank cutting and welding stuff!!!

[sugarwood]

These may help
Fuel Sender is fine. Open fuel gauge itself?
Gas gauge doesn't go below 1/2. Fuel sender does not appear stuck.

[Rodek]

I know this may not help but, my fuel gauge was bouncing all over the place. I added a can of seafoam to the fuel and it cleared it right up. 4 years now and no trouble out of the gauge.

[aston@ultrasw.c]

Dennis, you were 100% correct!

Standing on the tank had deformed the upper surface which forced the float tube against the back wall of the tank.

The sender was not new as I described earlier, I was getting my cars mixed up.

Anyway, on removing the sender, I could see that the float tube was no longer perpendicular to the mounting flange. It was creased right at the top where it fits over the flange. So I removed the tube and carefully tapped it back to shape over a piece of 1" tubing. Finally, I cleaned some light corrosion from inside of the float tube with scotchbrite.

Then I turned my attention to the tank. A length of 1 1/2" tube fitted well enough. I thought some force might be required but with a little pressure the tank popped back into shape.

On reinstalling the sender unit I noticed that the slightest tilt would cause the float tube to bang against the tank. Maybe I could have tweaked the tank some more but I decided against it.


Easing the tank back into shape:





Damage to float tube (after repair )

[john walker's workshop]

Another thing that will kink the tank is a blocked breather hose. I replaced a tank recently that was sucked down about 4 inches by fuel pump suction and no venting to let air back in.

[aston@ultrasw.c]

Originally Posted by john walker's workshop

Another thing that will kink the tank is a blocked breather hose. I replaced a tank recently that was sucked down about 4 inches by fuel pump suction and no venting to let air back in.

Hmmm, not sure about that.

Gas is volatile and creates a positive vapor pressure in a sealed container. Also, when fuel is pumped out of a sealed tank the pressure drops. So what is the net effect

[john walker's workshop]

What else would explain that? Other than an elephant stepping on it.

[Dodge Man]

I installed a new sensor that had a hang-up problem. I have the proper factory vents so the flange was flat. I had to remove the sensor exercise the float up & down by hand to BREAK IT IN for about 10 minutes. Even after fixing your flange issue you may need to exercise the float to keep it moving freely. Best of luck.

[whiterabbit]

Originally Posted by john walker's workshop

Another thing that will kink the tank is a blocked breather hose. I replaced a tank recently that was sucked down about 4 inches by fuel pump suction and no venting to let air back in.

Reopening this thread. What is the best procedure to ensure the tank is venting. I have a 1984 ROW and am finding it difficult to trace all the venting. Is there a recommended safe bypass?