Fuel sender floats

[GregR]

I need to replace my fuel sender in an old (44 years young) vehicle. I am seeing sending units with floats made of brass, cork, and plastic. Many reviews from users say to not use a float arm with a cork float. Brass is subject to pin holes. Plastic… I can’t find and info on longevity.

My question is plastic fuel floats - do these last a long time sitting in fuel 24x7? I don’t see what type of plastic these are made from to see how they react to fuel. I have to think the makers of these produce them knowing the environment they will be in.

Does anyone have and data or experience to share on these plastic fuel floats? Dropping tanks and replacing these is no fun do I prefer a solution that’s going to last a while.

 

[Timmastertech]

Every production vehicle today has a plastic float for the level sensor. I have never replaced a sending unit because the float sank. Usually the alcohol in the fuel kills the resistor card first.

 

[Vercingetorix]

Holley makes a universal laser sensor. Have no idea if that helps in your case.

 

[Chris142]

Nothing wrong with brass floats. They last decades.

 

[Opelman]

How many cars for how many years have plastic fuel tanks? A plastic float won't be an issue. Only one I would avoid is the cork as I have had the "fuelproof" coating fail and the cork absorb fuel and sink.

 

[Marcozi]

Here's the issue: the new float has to have the same buoyancy as the cork float. That is, if the new float floats "better," the fuel level will read high. Conversely, if the new float floats "less," then the fuel level will read low.

 

[eljefino]

Here's the issue: the new float has to have the same buoyancy as the cork float. That is, if the new float floats "better," the fuel level will read high. Conversely, if the new float floats "less," then the fuel level will read low.

That'll be a difference of maybe 1/4 inch over ten-plus inches of travel.

Go with the plastic float-- they make gas tanks out of plastic. They make gas cans out of plastic. It holds up.

I had a sunken brass float in my Ford RV. Fixed it by disassembling a couple of small engine carbs and safety-wiring their plastic floats to the arm.

 

[Nukeman7]

Every production vehicle today has a plastic float for the level sensor. I have never replaced a sending unit because the float sank. Usually the alcohol in the fuel kills the resistor card first.

^^^ Before assuming the float is bad, you need to remove the sender assembly and test the resistance readings across the full range of travel for the float arm linkage. 99% of the time a fuel gauge sending unit goes bad, it is due to corrosion of the resistor windings, not the float itself. In fact, I don't ever recall having a defective float on anything other than an old lawn mower carburetor.

 

[GregR]

Thanks for all the input. I tested the sender resistance and it was fine. Float was sitting on the bottom of the tank. I went with a plastic float and it works fine. I looked at the brass float removed and it had more than one pin hole in it. All done and gauge reports correctly.