Fuel Tank

[Allan Parkhurst]

I found a 1948 Dodge B1 Parts Book at a car show yesterday,it had some fuel system pictures. Thought I would share the picture.

[Allan Parkhurst]

I will try link to Photobucket. http://s93.photobucket.com/albums/l79/allanparkhurst/B1B%20Fuel%20Tank/

[Desotodav]

Great pictures Allan. I'm curious as to what the manual looks like that the photos came out of though as none of my manuals have that sort of detail in the areas you have outlined. Are you able to post a photo of the front cover of your new manual so that I can try to locate one?

Desotodav

p.s. Thanks for the B1 series wiring details pdf that you posted sometime ago. It was most helpful in the installation of the wiring in my 51 DeSoto truck.

[ggdad1951]

hey that shows the seal between the tank and the cab floor, which verifies the one I pulled off my '48 was authentic. I should get some dimensions off of that thing and whip out a pdf, if I can find it again

I assume it's similar to mine, I know where mine is, would you like a drawng?

[Allan Parkhurst]

http://s93.photobucket.com/albums/l79/allanparkhurst/B1B%20Fuel%20Tank/

I updated the Photobucket file with a few more. There are about 20 good discriptive pictures from this book I can update if anyone wants them.

[Desotodav]

Thanks again Allan, I know which particular manual to look for now. I have numerous truck manuals already but your recent acquisition appears to contain different info that that which I have.

Originally Posted by ggdad1951

I assume it's similar to mine, I know where mine is, would you like a drawng?

I'd be interested in a drawing Mark if you manage one.

Desotodav

[ggdad1951]

Thanks again Allan, I know which particular manual to look for now. I have numerous truck manuals already but your recent acquisition appears to contain different info that that which I have.

I'd be interested in a drawing Mark if you manage one.

Desotodav

Ok, I'll do one up today/tonight and have it for you tomorrow.

[Desotodav]

Mark, did you happen to find your fuel tank/cab floor seal (14-86-60). I'd still appreciate a drawing if you can manage it. I have my seat out at present as a result of fitting the 802 radio.

Desotodav

[ggdad1951]

here ya go:

[Desotodav]

Thanks Mark. How thick is the rubber?

Desotodav

[ggdad1951]

.100"

[Desotodav]

Thanks mate. I'll make one up during the week while the seat is out.

Desotodav

[JBNeal]

A couple of days ago, I accidentally found my old gasket in one of the work benches in the barn where I had hid all my gasket making stuff. This gasket came off of the '48 1/2 ton and matches the catalog view. The material appears to be a closed-cell foam rubber, as it is still spongy albeit crusty. I used the Google SketchUp program to jot this out while watching Lethal Weapon 4 on the TV during lunch today. It's a basic sketch to get the seal around the tank as well as the lip that holds the gasket square to the side of the tank under the filler neck. I recall trying to make one for the '49 1 ton, but the cab mounts are so worn that the original was way too thick; I ended up using an old inner tube as a temporary until I replace the mounts.

[ggdad1951]

mine just lay on the floor and buts up against the seat support ring.

[JBNeal]

the fuel tank/cab floor seal (14-86-60) mounts to the fuel tank as shown in the catalog listing, and is compressed between the top of the fuel tank and the underside of the cab floor to keep moisture from water-covered roads, as well as dust. A thin seal placed on the inside of the cab on the floor can be used with the same effect if it's sealed to the cab with a silicone caulk.

[Desotodav]

Good job, thanks 49D.

Desotodav

[Merle Coggins]

What's the purpose of the lip on one end? When I was setting my cab on, with the tank already installed, I had a piece of foam that was around 1" or 1 1/2" thick. I cut out a square piece with an oval hole in the middle to fit around the filler neck and it seems to be working just fine. It's not rocket science here. Just need someting to fill the gap. You can't see it once it's installed, and you add some floor covering, anyway.

Merle

[Desotodav]

Looks like the lip on the end just goes down over the edge of the tank Merle - maybe to hold the piece in place? (see post # 9 for picture). Strange looking part though!

Desotodav

[JBNeal]

the seal installs beyond the side of the tank, and the lip braces the seal against the side of the tank and the bottom of the cab. Without it, the foam rubber would eventually sag on that end and the filler neck area would not be completely sealed. I made a piece without the lip out of some closed-cell foam rubber, and though this foam rubber is much stiffer than the original, it has sagged in this area but is still sealing the cab.

Agreed, this is a part that is not seen so accuracy should not take a back seat to functionality. There are better materials available now than 6 decades ago, so creativity + low cost would be more prudent than trying to reproduce the original part.

My next approach is to make this seal a two-piece design: a flat piece of closed-cell foam rubber for the filler neck cutout, and a second piece adhered to the flat piece to act as the lip. The only reason I'm sticking with the closed-cell foam rubber is that I scored a wore-out work station mat at the machine shop that I grabbed off of the top of the dumpster.

[ggdad1951]

all mine had was the thin one in the cab, it had nothing, nor any remains of anything, between the cab and the tank.

[JBNeal]

while cleaning & organizing in the garage, I had these fuel tank seals in the same place so I thought I'd display them.  I have an old stiff mudflap that I cut to mimic the original (but it was too thin so it just rattled atop the tank), the original spongy rubber type that was on the '48, and a replacement that I made from a chunk of an old work station floormat.  The original appears to be formed as shown in the parts manual drawing, and it has the indentations from being pressed onto the underside of the cab.  When mounted on the non-B4 style fuel tank, the original gasket fits neatly around the tank neck and the adjacent formed area so as to fully contact the underside of the cab, completing the seal.  Without that extra lump of material, a flat gasket will eventually droop in the area that would be under the fuel neck hose, forming an incomplete seal.  I looked at the B4 Spring Special & it appears to have a flat piece of rubber about 1/8" thick on the inside of the cab at the fuel tank neck, but I don't know what is under the cab without removing the tank.

 

As can be seen from the remnants of my original seal, the spongy rubber could split and the seal could slide off of the neck.  I'm gonna guess that this happened on every truck that was driven on wet or dry roads, and the Dodge engineers decided to get away from this formed seal to a simpler (cheaper) rubber seal that just covered the gap.  I think the only reason I have this seal is that my great-grandfather was a notoriously slow driver (think of the geezer who gets in the way in the bayou chase scene from Live & Let Die) and the original seal was never slung off of the chassis from going around a corner or flying over railroad tracks.  The original seal material is still spongy, but the surface is crusty like melted plastic that has cooled off.  It's not so much like foam rubber as it seems to be like foam asphalt, if there ever was such a thing.  The material can be squeezed flat and feels like it gums together, but after a few minutes of sitting on a table, it expands back to its original shape.

 

With the variations in what has been found out in the field by fellow forum members, I cracked open the parts book and tried to figger out which variation is correct.  And it looks like there are several correct versions, as 14-86-60 has 3 listed part numbers in the parts book I have that was printed Jan.'53.  There is a part number for the early B-1s; another part number for the late B-1s & early B-2s; and another part number for late B-2s, all B-3s & all B-4s.  This may be another instance similar to the steering gearboxes, as the parts & shop manuals show a graphic indicative of early B-1 usage, but later B-series models have different parts used that look similar but are not the same as the graphic shown simply because Dodge did not update their literature.

 

At any rate, only us pickers of nits will know the difference and can testify what is correct and what is homemade to this part that is rarely seen...as long as it keeps the rats from chewing the stuffing out of the seat, I reckon drivers can use whatever works best for them

 

[Merle Coggins]

I had no reference to go by when I was assembling my truck. I don't recall if there was even anything left of a seal when I removed the tank during disassembly. When it was time to set the cab on the chassis I found a piece of foam material laying around the shop. It was 2 or 3 inches thick. I cut a piece similar to yours and set it over the neck, then set the cab in place. It's worked perfectly ever since. Once everything is in place you can't see it anyway.

[Desotodav]

A very interesting story Brian. I haven't located a gas tank/cab seal in any of the 8 trucks that I have owned. I was looking into them a while back when the topic came up but ended up not installing one. I managed to get the seal measurements from a member here (but I can't remember who) and even made a template up. I ended up installing rubber internal mat and cutting it as close as I could to the filler tube behind the seat and left it at that. I have come across a couple of trucks with a flat rubber piece screwed down to the floor closely fitting around the fuel filler pipe behind the seat.

Could it be that the crusty surface of your original seal is a reaction from age, heat and also petrol fumes?

[Jeff Balazs]

Well to muddy this up a bit.......the opening through the floor in mine clearly had 4 holes around it which looked like they were made at the factory. I just reused them when I made my cover plate from 1/8" aluminum. I made a gasket from inner tube material and the whole thing is as close to watertight as is possible.

The advantage of doing it this way....above the floor .... is that any moisture which might make its way to the top of the tank is not trapped in this location by a thick piece of rubber,etc. Having replaced a few below deck fuel tanks in boats......the worst external corrosion is always found where they are supported or restrained by thick rubber, etc.. pads.

 

Jeff

[JBNeal]

the original B-1 seal in theory was to compress between the top of the tank and the bottom of the cab so as to not allow any moisture to collect on those metal surfaces, much like a flange gasket.  But the spongy rubber material Dodge chose would shrink over time, allowing moisture & debris to collect, the seal would sag and eventually tear as shown and fall out of the truck.  The thinner rubber seal used in the B-3s etc. is much cheaper to fabricate, install, and replace.  The four holes are also in the B-1 cabs, and they must have served some purpose as other holes have been located and questioned.  My guess is that these four holes may have been for locater pins on an alignment jig at the factory so that the cabs were aligned uniformly from one truck to the next, allowing the fuel tank to be properly located so that the sending unit can be removed from inside the cab as well as quick & accurate installation of front sheet metal, etc.  Then again, these holes may have been for supplemental ventilation for all the cig smokers back in the day