Fuel Tank Questions for Wagon

Jwawhite

Jwawhite

Well-known member
Dropped the Frankenwagen fuel tank yesterday, discovered a few things.

The fuel sender has the incorrect Ohm Range.../340 vs /10, now why install a wrong sender? Ordered the correct one today.

The tank has a leather strip glued to top of tank between top of tank and bottom of spare tire compartment. There are bolts holding the tank off brackets towards front and one bolt at rear on crossmember. The strap is located R side towards rear bumper.

Any clue as to why? Should there be one at all four corners of tank? It measures roughly 4" long 1.25 W and about 1/4" thick. My shop manual does not show a Wagon set up.

Any idea how the correct sender is wired?

Tank bib 5/16 will be soldered soon, no more leak!
 
The '55/56 wagon models have a tri-pod mounting arrangement for the gas tank.
At the front, there are two "C" brackets. Each has two bolts at top and two bolts at bottom. At the rear there is one "L" bracket that has two bolts holding it to the rear frame crossmember at the center. There is one bolt holding the gas tank. These three brackets are made of heavy guage metal.
The original sending unit has a push-on terminal at the center. Connect only the wire from the fuel guage to this terminal (although that terminal can accept two wires). The reason for that is, originally, the factory had a small RFI suppression condenser mounted to one of the fuel sender mounting screws and the wire from the condenser plugged into the second push-on terminal.
I also ran a second wire from the main grounding terminal on the firewall all the way back and connected it to both taillight and backup light housings, the license plate light housing and to one of the fuel sending unit mounting screws.
Without that ground wire, the fuel sender is relying upon your metal fuel line for ground.
 
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As far as the insulating pads between tank and floor, the factory may have applied the strips in various ways depending upon how the tank fitted.
I was a little creative when I installed my repro tank in the '55 Courier. I glued thick foam-rubber gasket material across the front at the top and two strips of lighter foam insulation material at the top along the sides of the tank. I also glued a strip of roofing felt all across the front to keep road crud from building up on the front of the tank.
The factory installation (using the rigid rubber strips) places a bit of tension upon the three mounting brackets. My foam rubber installation does too, but quite a bit less, and still provides a good seal between tank and floor.
 
Daves55Sedan, that's how my 56 is set up except too, except for the wiring.

I have one wire from the two wire loom attached to a central stud on the fuel level sender, the other just dangling and a solo wire from one screw on the plate, again from sender, to frame.

The fuel gauge is operable but once you get just below a half tank reading, she is near E.
The new sender I ordered from Carpenters should fix this.

What should be done with second wire out of the loom? Ground it to one plate screw?


I guess I'll know more if I get the NOS from Carpenters-- if it has that RFI.
 
The factory wiring goes like this:
Power wire to (+) side of fuel guage, then switched wire from (-) side of fuel guage to the sending unit push-on terminal. That is all. The factory did not include an extra ground wire to the sending unit case. They relied upon ground being carried from the sending unit screws to the tank itself, then to the fuel line which is attached to the frame. The frame being grounded at the back of the front crossmember with a heavy gage wire connected to the engine front steady-rest bracket. The engine is also grounded to the body with a heavy wire from the back of the cylinder head to the firewall. If some of that stuff is missing all these years later, you should look at ways to duplicate it somehow.
The factory only had ONE wire connection to the sending unit (not counting the RFI suppression condenser, which is mounted locally).
I added a second ground wire from the sending unit metal case to the firewall stud (which is grounded to the engine) as previously described. I did this because my car frame was sandblasted and painted, and the brackets that hold the fuel line to the frame were stripped to bare metal and painted prior to re-assembly, so the electrical continuity might not have been good between the fuel line and the frame. AND I did not want to rely upon the fuel line as ground anyway.
I custom made my own dashboard-to-rear bumper wiring harness including the extra ground wire and accessories that I added for the rear window defroster and automatic cargo light using all new 12 gage wiring. It is probably double the size of the original wiring harness.
 
As far as the tank mounting insulator strips, I say this:
The purpose for them seems to have been reducing noise and friction between top of tank and bottom of spare tire hide-away compartment.
The hardware stores sell rolls of self-stick foam strips in various thicknesses (up to at least 1/2 inch). I got a roll and cut a strip long enough to run the length of the top and stuck them on top of the tank near the sides. For the front, I cut down a strip of leftover door gasket foam rubber and glued it on to the top across the front side of the tank so that the gaskets would rest against the bottom of the floor on those three sides of the tank. They keep out dirt, rain, snow, road tar, etc and there is no noise or friction when the wagon goes over a bump in the road.
 
Dave....I am in the process of mounting my new repro fuel tank to my 55 Ranch Wagon.
Great idea for the insulation on top of the tank, I will do the same.
Quick question on those two front brackets. They are C shaped , should the gas tank flange be inserted into the C opening and then bolted. Or should the gas tank flange just stay below the C and be bolted to the lower side of that C bracket?
Thanks for your reply.
Steve
 
Steve, my tank was mounted to the bottom of the brackets, lets see what Dave says. My car was kinda slapped together.....but it's better today!
 
Those two "C" brackets have "legs" at top and bottom where the bolt-holes are. Those legs seem to be slanted a little bit such that the main web of the bracket slants toward the rear at the bottom. The "C" brackets should be installed with the "legs" facing toward the front.

If the brackets were turned around so that the legs faced rearward, it would be extremely difficult to poke the bolts thru the holes no matter whether you had the tank on the bottom of the leg or above it. Furthermore, it appears to me that the mounting flange of the gas tank is a little bit wider than the width of the leg on the bracket. So if you had the bracket turned around the wrong way, the tank flange would hit the web of the bracket before you could get the bolt-holes to line up.
The "C" brackets should be bolted in so that the "legs" face forward. Then just lift the tank up and align to the holes in the "legs" of the brackets.
 
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I installed my tank without the filler-neck attached. I don't think you could do it unless you had a crane pick up the back of the car, because that filler-neck is so long. Even if you did, it would be a bear to try to wiggle both that big hose and the little vent hose hookups to the tank while trying to hold the tank in mid air until you could get a couple of bolts in the tank mounting holes. Besides, the filler neck has a mounting bracket at the top which needs to sit on top of the mounting tab on the inner quarter behind the gas cap door.
The tank can easily be lifted with a cheapo two-ton floor-jack, just high enough to where you can still manipulate it's position to get the bolt-holes to line up.
Once the tank is bolted in securely, you can attach both it's rubber hoses securely at the bottom of the filler neck using worm-gear clamps (leaving enough overlap for the hoses to fit over the tubes on the tank. Then feed the tube down inside the opening where the gas cap door is and crush the hoses down onto the tank. Attach two more worm-gear clamps at bottom.
It's a one-man job.
 
Found one leather , Noise reducer? Friction reducer stuck to the bottom of my spare tire well. Looking down through the well, it was placed on the R side above the opening for the fuel lever sender. I didn't see any other marks/ locations on the underside of the well, I'm thinking perhaps 4? One each corner?
Used long wearing floor mat for replacement, cut to fit.
 

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I have seen both '55 and '56 wagon tanks removed. The factory did not apply the insulators consistently. Don't worry about how they did it.
As long as you know what the purpose is, you can configure something that fulfills the same principles.
The purpose of the insulators is to press the tank against the floor without scratching metal-on-metal. That means you need to get an insulator that will put a little bit of strain on the mounting brackets when the tank is fully mounted, crushing the insulator material.
I improved upon that by sealing the space between tank and floor from any possibility of water and road crud getting between them. You don't have to do that, but if you don't, you leave the fuel sending unit exposed to the elements coming at it while the car is in motion (rain, salt, tar, dirt).
 
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