VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 gas tank/sending unit cork float replacement

My float is 2 corks sitting on a wire. They look dry, and one has a slight split. I have a new set, but I can't figure out how to remove the old ones. The wire has a crimp, then a brass washer, then the float.
I researched and found this:
http://forums.aaca.org/f165/replacing-fuel-tank-floats-37-special-356120.html
They suggest filing the crimp, installing new float, finishing with a new crimp.
Is that right? Is there some other, easier way?

Cork floats don't live long in fuel with alcohol. My suggestion is to buy a cylindrical brass float with groove near one end from one of the part suppliers. The float was used in 40s Chevys. Heat the wire red hot to take out any temper and then bend the end in a circle just a little smaller than the groove in the float and then clip the float in place. I understand that the Filling Station sells a plastic float set to replace the corks. That is another option. I prefer the brass as it will survive alcohol gas just fine.

Thanks, Chipper, for that. I'll keep working on it.

I replaced the fuel tank and sender in my car 4 years ago. The replacement sending unit came with a plastic float and it has survived trouble free since. Most of the gas stations in my area have ethanol in the gas. Don

Probably looks a lot like this. This is the sending unit in my '38. The original sender in my car was toast & I found this on ebay. Before I found this, and another as a spare, I used a universal. I don't put ethanol in the car when I can avoid it. Often on tours I have to burn E10 because that's all that's available. So far it's holding up fine.

Yep, Tiny, that's pretty much my sending unit. I think I'll go ahead with what I bought, the 2-cork float to replace the same thing. Nobody really answered my question, so I guess I'll follow the procedure they suggested on the link I included.
BTW, my BP station agrees, all the gas has alcohol in it.
I sure hope I'm on the right track. It was a lot of work removing the gas tank, and I can't see a way to removing the sending unit without taking out the tank itself.

The sending unit comes out the hole it sits in. No need to remove the tank. I've had mine out several times. It's impossible to get it back in wrong as well. While it looks like the holes are evenly spaced they aren't. It'll only fit one way and get all the screws lined up.

I just did the new fuel tank and sending unit on my 39. The only way to take the sending unit out is by dropping the tank. It would be hard to see the 5 screw if you don't. Got the sending unit from 40's Chevy. I was going to replace the corks. But I read what you said glovebox and thought its a lot of work and I'm not sure if I would do it right. Also thought the cork would flake off in time and clog the fuel line. So I went the new one route with the brass float.

It may be the difference between your coupe and my sedan. I just didn't see enough room to move around up there, without dropping the tank. Besides that, after removing the sending unit, I had to scrape hard, to remove all of the old gasket residue; I can't imagine doing that with the tank still in position. But when I reinstall the tank, I'll reevaluate my ability to pull the sending unit alone, if I have to do this again.
Again, Tiny, I would like to know if I'm headed the right way on installing the new cork float?

Hey, Twigs, do you have a sedan or a coupe? I think that's probably the point, there must be more room on top of the coupe's gas tank. I can't see a way to deal with my sedan's sender, without pulling the tank.
I kind of wish now, that I'd bought a brass float. FWIW, my corks did not flake off; they just look very dry, and one of them has a small split.
I was also getting false gas gauge readings. My dash said 1/4 tank, but the tank itself was empty. I don't think that's the float, though. I'm going to attach a ground wire to the sender. Maybe that will put the tank and the dashboard back on speaking terms with each other.

I just replaced the floats in the tank of my 39 and they are made of cork. The F.S. assured me they were alcohol safe.
I removed the small clip and pulled the two old cork floats
off put the new ones on cleaned the rod and soldered a small
washer to the end,but they were so tight to start with when
I pushed them on the rod I think they would have stayed without
the solder.
When the previous owner ? must have changed the sending unit
he cut a hole in the trunk floor and put a plate over it, Now
when or if I need to check the wiring or the sending unit all
I have to do is raise the trunk mat undo six screws and I'm
there. You might want to cut yourself a hole for easy access the next time you need to work on the sending unit or wiring. Good Luck......

Silly me for not asking. The coupe has the tank in the trunk, not under the car. The sending unit is accessed by a steel plate in the raised floor of the trunk. I'll sneak out to the garage & take a look at the floats on my extra sender to get a better feel as to how I'd remove them if I needed to. When you get your sender out you can check it with an ohmmeter. Full position should show full resistance of ~30 ohms and empty should be ~0 with smooth movement between both extremes. If the movement readout is smooth but stops well above 0 in the empty position you can adjust the sender one tooth at the gearing by carefully moving the float gear one tooth. Below is the trunk of my coupe. The tank is located below the board just aft of the seat toward the passenger side. The ~3" diameter plate is the access cover for the sending unit. Below that is the tank without the board in place.

This is completely FWIW, but I have an elderly Pontiac whose sending unit was acting up a while back. Based on the supplier's assurances that cork was AOK in alcohol, I went with it. Big mistake. When I had the same problem with my Chevy, I did exactly what Chipper did. It really is not as difficult as you might fear and there really isn't anything to go wrong with it once you are done. My thought was that I already know that cork is not foolproof or I wouldn't be fixing it, why invite the same problem?

By the way, I have the exact same problem as glovebox, 1/4 means empty, but I just can't see replacing the original for the convenience of accuracy, I just top off a little more frequently to avoid issues. Good luck with the project.

Even if the supplier has the best of intentions and will stand behind his products that does not generally include the labor to R&R the part.

The traditional coating (originally used in our old Chevys) for cork gas tank floats is shellac. Shellac is resin (from Lac bugs) dissolved in ethanol. Shellac was used to reduce the transmission of gasoline into the cells of the cork. As the cells get filled the cork begins to sink. The gasoline also deteriorates the cell structure of the cork. For this discussion suffice it to say that ethanol and the water it attracts does not reduce the rate that cells are filled. So what do you use if shellac is not a good coating for cork in gasoline tanks? I tried gas tank sealer. Yes the alcohol resistant "snot". I always had a problem with the float sticking to the bottom of the tank when the gas level got low. Kicking the bottom of the tank would dislodge it so it indicated the correct fuel level. After a couple of years when the sealer began to peel off the tank I checked the float. It was after the tank had been drained and dry for a while. The coating was still there but the cork had shrunken and pulled away from the coating. The cork was dark colored and crumbly.

I had experience with urethane foam carburetor floats (sinking) from the 80s and later so didn't want to go that way. So having a couple of brass floats I decided to see if I could substitute one of them for the cork. In the first case I found that a wire coat hanger was the right size and stiffness to replace the wire on a '28 gas gauge. I bent one end of a wire in a nearly complete circle slightly smaller diameter than the groove in the brass float. Put the appropriate bends in the wire to duplicate the position of the float center and crimped the wire in place. So far the gauge has been accurate, does not stick so, I am satisfied with the modification. Wrote an how to article with photos and submitted it to the G&D two years ago but it never got published.

I really appreciate all the responses to my question. I think this is about the most helpful thread I've participated in so far.

My 39 is a 4dr sedan...I was getting faults reading too..thought maybe it was the wiring..I have not tried to see if things are ok yet..I'm also doing brakes at the same time.
Hey you would have a right side Extension strut laying around.

This is a picture of a left side...

sorry, no, I don't have one.

Hey, Chipper, sorry to bother you again, but you've pretty much sold me on going with the brass float. Now I need help on which one. I've found Jim Carter trucks, 1-3/16" x 2-1/2". They pitch theirs as "not the short Ford style we have often seen on the market."
Chevs 40s and Filling Station have one, roughly same diameter, but only 2" long. I researched some more, and the 2" size is being sold elsewhere for 1967-1973 Ford products (mustangs and cougars).
I notice all sites are selling the cork floats for my 1938 pre-war car; the brass is for post-war, 1947--1972 vehicles). My tank is 14 gallons, but post-war looks like 16.
I'd prefer the Jim Carter version, but you sure seem to have more experience, so your thoughts here, please.
(My guess, FWIW, is that 1/2" isn't important, in a 14-gallon tank. But then, as my kids tell me, what do I know?)

The difference in float volume is not that important. At most it would have the larger float a bit higher on the surface. The difference in bending the wire is likely more important on the gauge reading.

Thanks.