Fuel sending unit float will not float.
 

My new-to-me 37 street rod came with a bad fuel sending unit for the aftermarket gauge. I have cleaned the sender's variable resistance parts, and an ohm meter shows the electronics are now working properly. But there is another problem: the float sinks like a rock in gasoline. The float appears to be some type of solid hard rubber. Why does it not float?

All the available sending units I have seen have five mounting screws. But my unit has six screws into the stainless aftermarket fuel tank with six tapped holes. What's up with this? Was six hole standard in the past? Are there six hole sending units available today?

Re: Fuel sending unit float will not float.
 

i would keep the sending unit and replace the float. Post a picture so we can see what type of sending unit you have

Re: Fuel sending unit float will not float.
 

6 bolts is stock early Ford. Most (all?) modern tanks use a 5 bolt. There are adaptors to convert the old 6 bolt to use the newer 5 bolt sender. See the link below.

http://www.tanksinc.com/index.cfm/pa...rod/prd344.htm

Re: Fuel sending unit float will not float.
 

Great advice. Not the same situation, but I fought replacement sending units on an original-ish '36 about 8 years ago. Finally I just took the float off the replacement and put it onto the original sender. Bang, Zoom, Done! Well except for the calibrating fun.

Re: Fuel sending unit float will not float.
 

X3. The Model A distributors have a neoprene float to replace the old cork sinkers. Chap

Here is what I am talking about:
https://modelastore.com/index.php?ro...roduct_id=3906

Re: Fuel sending unit float will not float.
 

Jay,
I replace the plastic float with a Ford 94 carb float, very close the factory float....I solder the float to the swing arm.
Charlie ny

Re: Fuel sending unit float will not float.
 

I look in the trash for floats---modern car fuel pump assemblys usually also have the fuel sender too, I pop the arm and float off of them, the section of arm can be used to repair rusted off ends

Re: Fuel sending unit float will not float.
 

Thanks for the advise, guys. I ordered a float today from Joe's. (along with a bunch of other small parts I have been waiting to order) Joe's catalog has both the original 36-48 brass float, and a "solid modern type". I ordered the solid type. The float arm I have is actually too long for this shallow tank, so the excess should be enough to wrap around and hold a solid float. If not, I'll figure out some other way to float the boat. Improvise!

Re: Fuel sending unit float will not float.
 

Welcome to the ‘Barn. Mike

Re: Fuel sending unit float will not float.
 

I too adapt a modern float to the old arm.

Re: Fuel sending unit float will not float.
 

I used a unit from Joe's the six holes didn't line up exactly so I drill a few holes to make it if works fine just takes a while for the gauge to move when full could be my fault but it's ok

Re: Fuel sending unit float will not float.
 

Put a large soldering iron on the brass float to
get it hot. The gas will expand and come out the
seam or crack. Get it all out and solder leak. I got
stuck on the road once with the float sunk. Held it
behind the exhaust pipe of a modern car until all the
gas was gone. Turned the float upside down and was
able to go to the show and make it home. G.M.