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68 Charger fuel tank vent issue....

  
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68 Charger fuel tank vent issue....

 
jclaus68 jclaus68
New User | Posts: 33 | Joined: 09/09
Posted: 05/01/13
07:50 PM

Gentlemen, I'm really hoping someone can shed some light on this subject, because I'm about at the end of my rope with this.  I've got a 68 Charger, with the flip-top, non-vented gas cap.  Where I'm running into issues is with the tank itself.  The gentleman I purchased the car from several years ago ordered a new, repro fuel tank for it and installed it.  The genius installed it with the old, nasty sending unit and gasket and the old nasty filler tube gasket.  It was because of this that at the time, I never had a problem with the tank because the tank could easily "breathe" through the holes left by these old gaskets.  Once I had to replace the trunk pan and while in the process of, replaced the filler tube gasket and the sending unit and gasket, I developed a serious problem.  Everytime I would take the car out on a warm day, when I would stop at the nearest petroleum station to fill 'er back up, the tank would release a mountain of vapor trapped in the tank.  This expansion and contraction of the metal tank soon lead to it collapsing on itself and as a result, developed a crack that caused a leak.  Since I had to order a new tank, I told myself I was going to get the correct tank with vent tubes in order to properly vent the tank to the atmosphere.  However, it would seem that no such tank exists for the 1968 Charger???  I contacted the manufactuer of the tank, I've contacted the parts warehouse that I ordered the tank from and I've scoured the web in search of a tank with the filler hole in the right place and vent tubes up front and no such tank exists.  Can anybody tell me what I can do?  Is there a cap I am unaware of that will vent the vapors properly?  Or is there a tank that only one person sells out of their garage that has the vent pipes and the filler hole in the proper location?  HELP!  

waynep712222 waynep712222
User | Posts: 127 | Joined: 04/13
Posted: 05/01/13
10:42 PM

welcome to the world of lots of vapor blended in the fuels..

i will have more in a few days but let me see what i can create tonight..

you might want to check the sizing on a 70 charger fuel tank with EEC..  as that will have vents but also require a fuel separator assembly..

Images?Q=Tbn:And9gct P5ailgudc2iwm 95Lxg54zz3qmxqktm U9lhmxpoy Oysad3

so when you go around corners.. you don't have direct fuel slosh into the lines into the carbon canister... as you don't want the fuel vapors leaking out .. but you do want them properly vented..

since this  is at the top front of the tank... only somebody who crawls up under your car will ever see it..

since replacement 68-70 tanks also came without  the EEC vents..

you have the choice to punch a hole there..   you could silver solder on a 1/8 NPT or 1/4 NPT bung where the vents are on the the other tank... drill thru a compression type fitting to remove the stops inside..   so it will be what ever NPT male x compression tube...  now... with a length of steel fuel line tubing thru the fitting you could insert it thru the opening.. thread the tapered pipe threads into the soldered on bung fitting..  since you put a bend in the tubing... so the section inside the tank is at the highest part center... you now have a vent tube in the tank... over the next day or two i will create a drawing to show you how easy this is..

you could also use a bulk head fitting with the tube going all the way thru.. but that gets more complicated..

there are a few silver bearing solders that have a very low melting point.. like 460.. and are VERY STRONG...  i use one type to fix broken eyeglass frames for friends..

you could also install a vent tube thru the side of the filler neck  that leads down into the tank and upward inside the tank..

there are small carbon canisters usually found on japanese cars that can be stashed fairly easily..   so you should be able to stash it up high between the rear quarter and the wheel well..   you can also get some purge control valves if the carbon canister does not have them..

let me know which way you might want to go.. must get some sleep now.. long day tomorrow.  

waynep712222 waynep712222
User | Posts: 127 | Joined: 04/13
Posted: 05/01/13
10:56 PM

P1010006 6


Fuelvent

Attachment


16793



These are JUST IDEAS... its your car and your decision... i don't want you FUMING about this vapor issue  

jclaus68 jclaus68
New User | Posts: 33 | Joined: 09/09
Posted: 05/02/13
08:29 AM

Gentlemen, thank you both for your input, unfortunately, we are all on the same page, which is modifying the tank I've got or getting a different one.  Wayne, thanks for those graphics, I've seen the bottom one before and they both tell the same kinda story.  And trust me when I say, I've definitely been FUMING about this vapor issue for several weeks!  Thanks again guys!  

69_340_GTS 69_340_GTS
Enthusiast | Posts: 535 | Joined: 06/09
Posted: 05/02/13
09:36 AM

They put all this junk on a '68? My '69 Dart does not have, and never had, anything like that. Why not just put a vented gas cap o it and be done with it?  

jclaus68 jclaus68
New User | Posts: 33 | Joined: 09/09
Posted: 05/02/13
02:49 PM

340 GTS; that's exactly what I'd like to do, but with a 68 Charger, the gas cap is the flip top cap that is non vented.  The filler tube has the rolled inner provisions for a twist type cap that could be vented, but not the case for my Charger.  As such, I've gt a whole list of issues I have to work around to get the tank to vent properly.  Fun stuff.  

69_340_GTS 69_340_GTS
Enthusiast | Posts: 535 | Joined: 06/09
Posted: 05/03/13
05:13 AM

On my Dart, there is a small tube connected into the side of the fiiler pipe, near the gas cap. Not sure where the tube goes, never paid much attention to it, but it sure looks like it would act as a vent. Something like this picture:418Gwbjripl  

jclaus68 jclaus68
New User | Posts: 33 | Joined: 09/09
Posted: 05/03/13
03:22 PM

Yep, mine has a similar setup, thats the filler vent line, that connects to the nipple on the sending unit to transfer air to the top of the filler tube as you fill it with a fuel pump.  However, since mine has no vented cap, once the cap is on, there is no vent to the atmosphere to vent the vapors that build up as the temperature of the gasoline increases.  

waynep712222 waynep712222
User | Posts: 127 | Joined: 04/13
Posted: 05/03/13
11:33 PM

put a TEE in the vent line hose...  or in the tube...  

70RT440U 70RT440U
New User | Posts: 1 | Joined: 09/13
Posted: 09/14/13
09:32 AM

Icon Quotewaynep712222:
welcome to the world of lots of vapor blended in the fuels..

i will have more in a few days but let me see what i can create tonight..

you might want to check the sizing on a 70 charger fuel tank with EEC..  as that will have vents but also require a fuel separator assembly..

Images?Q=Tbn:And9gct P5ailgudc2iwm 95Lxg54zz3qmxqktm U9lhmxpoy Oysad3

so when you go around corners.. you don't have direct fuel slosh into the lines into the carbon canister... as you don't want the fuel vapors leaking out .. but you do want them properly vented..

since this  is at the top front of the tank... only somebody who crawls up under your car will ever see it..

since replacement 68-70 tanks also came without  the EEC vents..

you have the choice to punch a hole there..   you could silver solder on a 1/8 NPT or 1/4 NPT bung where the vents are on the the other tank... drill thru a compression type fitting to remove the stops inside..   so it will be what ever NPT male x compression tube...  now... with a length of steel fuel line tubing thru the fitting you could insert it thru the opening.. thread the tapered pipe threads into the soldered on bung fitting..  since you put a bend in the tubing... so the section inside the tank is at the highest part center... you now have a vent tube in the tank... over the next day or two i will create a drawing to show you how easy this is..

you could also use a bulk head fitting with the tube going all the way thru.. but that gets more complicated..

there are a few silver bearing solders that have a very low melting point.. like 460.. and are VERY STRONG...  i use one type to fix broken eyeglass frames for friends..

you could also install a vent tube thru the side of the filler neck  that leads down into the tank and upward inside the tank..

there are small carbon canisters usually found on japanese cars that can be stashed fairly easily..   so you should be able to stash it up high between the rear quarter and the wheel well..   you can also get some purge control valves if the carbon canister does not have them..

let me know which way you might want to go.. must get some sleep now.. long day tomorrow.


This is somewhat of an old post, but I'd thought it was important to clarify a few things on this topic.

First, use EXTREME CAUTION whenever you apply any flame or heat source to gas tanks (i.e.: welding, soldering, etc.).  If you have a brand new tank that's never had gasoline in it, then go right ahead.  But on used tanks, especially half-empty or empty tanks, you will have quite an explosion (meaning you can KILL yourself) if you don't drain the tank completely and flush any remaining fumes left in the tank using either water (fill the tank and turn over a couple of times to clear out air pockets) or an inert gas (meaning non-flammable gas).

Mopar B Bodies came with either Federally mandated emission control equipment, or if it was born a California car, then must have emission control equipment required by California.  49 state cars came with Cleaner Air Systems (CAS) and California cars came with Evaporative Control Systems (ECS).  The difference is CAS did not have the charcoal canister and the plumbing that went with it, and the California-smogged cars with ECS did.

In a B-body Charger ('68 - '70), CAS gas tanks has a simple vent system that used a vent tube alongside the filler tube with a sealed gas cap.  The vent tube goes through the trunk floor/pan via a grommet into the hollow frame rail (vents to the outside underneath the car).  An ECS gas tank will have all kinds of plumbing to accommodate the charcoal canister and vapor return lines (I think there's 5 of them rubber hoses).

The Right Stuff Detailing (www.getdiscbrakes.com, or through Summit Racing) carries both types of gas tanks.  If you get the correct tank, you wouldn't need to do any modifications or soldering on the tank.

Hope this was helpful for someone.