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SpatzBuggy Samba Member
Joined: March 04, 2011 Posts: 5
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Posted: Thu Sep 18, 2014 5:19 pm Post subject: 72 STD 112 Fuel Hose routing, Vapor, Emmissions |
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This is my first post. I have been working on my Std 72 Bug for a while now and have been lurking through the posts for info on the correct original OEM configuration of my fuel vapor lines, expansion canister in the trunk and the vapor canister under the right rear wheel well.
I have found a bunch of info but I still can't quite get how to do this right.
So I will start with some photos and maybe some of you may be able to help me out here.
First of all, it has been difficult to locate photos of the correct configuration for my 1972 Std.
I think I have the rear canister connected correctly to the doghouse and the OEM oil bath filter.
Today I blew out the 3 metal lines with compressed air that start in the front trunk left side, under the front left wheel well, crosses over to the passenger side wheel well right where the passenger running board starts. I replaced a 2" hose there (it crumbled). Then back to the end of the running board for another short crumbly hose connection that leads to a line going around the right rear fender mount bolts and through a hose to the EVAP canister. I blew out each metal section as I went along the path toward the rear section.
My Fuel tank is a new replacement one. It has one small vent connection towards the front left side of the tank.
The right side of the tank has the filler setup, double hose, etc. I have a picture of how it currently connected.
[img][/img]
Note the orientation of the canister above. Lower vent is to bottom of the can, toward the rear and connected to the "T" fitting. (Also note this orientation in some of the following pictures and diagrams).
Not showing is the forward end of the canister which is at the top of the can. The can has its manufacturing seam pointing upwards.
Here are some diagrams I think come closest to my target:
The orientation of the can differs from mine, and I am not sure I know where I picked this photo up from....looks like original VW.
This one also differs from mine in orientation.
This one has the same basic orientation can orentation as mine.
The last one was a screenshot of a type II Haynes manual from an Australian site...this is the most basic diagram that I believe I have found.
Then some diagrams of what I believe are Super Bugs, which doesn't help because they use the fragile plastic expansion chamber...mine has a canister instead.
This one just confuses me.
This one dumps it out to the ground and or the air
This one is missing the canister and few reference points...what goes where?
I believe this one was from a 1990's Mexi-bug...the canister looks similar...maybe I could use this (or just rebuild my canister if I could find charcoal that would absorb the volitiles...maybe aquarium charcoal isn't best?
This diagram isn't too bad, but still leaves questions in my mind on how to route...the can is inverted from mine...maybe different year models? 1971 or 1973?
Here is a picture of the front running board hose location heading toward the rear, toward the left.
And this hose connection between the rear of the running board to the left taward the canister under the wheel well.
My cowl has some tabs, about 3 or 4 of them, that I believe hold a metal line crossing across the front edge of the dash. I picked one up from the junk yard in hopes that I would need it.
So do I take the front cannister connection (now at the top of the can) and run it through the new crossover metal tube, then toward the rear EVAP cannister?
Where do I route the gas tank vent to that is on the left front of the tank? and how does it route?
Once this is done I presume that gas expansion goes into the canister...so is my canister orientation correct?
Thanks for any help you can give me on this.
So if anyone has a totally stock 72 STD (mine was made June 1972 and has some items that I think were changed for the Super Bug...such as the Hazard switch on fuse 8 and 12 fuses in the box) and can drop some photos here, it would probably solve this problem I would like to close. |
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Tim Donahoe Samba Member
Joined: December 08, 2012 Posts: 11739 Location: Redding, CA
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Posted: Fri Sep 19, 2014 12:28 pm Post subject: |
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I have a 1974 Super Beetle with the smaller white-plastic expansion chamber, located just under the cowl. And I don't know for certain, but unless VW made some major changes to the system, the black tank that resides in your trunk may not have any charcoal in it.
My charcoal canister is the one in the back in the wheel well. The small one I've mentioned already is simply a sort of holding chamber for fumes and actual fuel. It's designed to allow raw fuel to enter (when you fill up your tank too full on hot days), and to allow the fuel to return to the tank (when you use up some fuel or the day gets colder). It also collects fumes that will be transfered to the charcoal canister in the back wheel well--fumes that will be stored in the canister's charcoal innards until you start up the car and the fan blows the fumes into your air cleaner, then carburetor.
Tim |
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flyboy161 Samba Member
Joined: December 26, 2009 Posts: 2091 Location: Perry, GA
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SpatzBuggy Samba Member
Joined: March 04, 2011 Posts: 5
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Posted: Fri Sep 19, 2014 4:23 pm Post subject: |
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Tim and Flyboy,
Thanks for the replies.
I believe you are correct in that the front can is simply a holding tank...when I tap on it, it sounds empty and hollow. So the charcoal is only in the rear canister.
It would seem to me that if the "rear hose connection" of the CAN were toward the top of the can, mounted at the angle that it is, that any vapor inside the can would rise up a hose that would be connected to it.
(So imagine flipping the can over 180 degrees. Top bung towards rear, bottom bung towards front).
That hose could route upwards, behind the hood hinge and into the metal tube.
The tube would be mounted on the top of the cowl using the clips located there already and across near the speedo where another hose on the drivers side of the metal tube would then drop around the drivers hood hinge there and head towards the exit to the rear canister.
This "up high loop" would provide a sort of "holding area" for fumes/vapors to collect (just like the Super Beetle uses in a more complex way).
Some of the vapors may condense in the metal pipe and drip back towards the can and repeat that cycle, or they may drip towards the exit to the rear...that pipe is sort of in an arc shape, so condensed fuel could drip either way. If it drips toward the drivers side, a pathway for liquid gas back to the gas tank would be a good thing.
On the drivers side, a "T" could be setup to allow the condensed fuel to run back into the tank bung located on the left front of the gas tank and I could recover it.
The center of that "T" could loop upwards such that only vapor might head towards the exit to the rear unless there is a whole lot of gas present in the crossover setup. As long as the doghouse fan is running, negative pressure will pull the fumes rearwards.
In this scenario, the can gets repositioned. The LOW bung would be toward the front of the car, and the HIGH bung would be towards the rear and on top. The filler "T" connection located midway in the smaller of the two parallel filler hoses would then route to the forward, low bung.
Does this seem reasonable?
Was that the stock setup on a STD 72?
Here are more pictures.
Front of can...current configuration. Goes over to drivers side "T"
Looking down on the filler hoses, passenger side...current configuration
Drivers side. Right to gas tank. Left goes to "can" front, high bung.
"T" center goes to "exit to rear"
Trying to work it out...
The target...
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flyboy161 Samba Member
Joined: December 26, 2009 Posts: 2091 Location: Perry, GA
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Posted: Fri Sep 19, 2014 4:54 pm Post subject: |
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As I suspected. Can is installed backwards. The low fitting should be forward, the high fitting should be aft. The plumbing is easy to figure out from there.
It is an expansion tank. Any liquid fuel from the tank should go in the low fitting forward. Vapor comes out the high fitting and is pushed Bach into the tank at the Tee around the filler and the test is sent aft to the charcoal canister where it is neutralized and routed to the air cleaner
You only want vapor going aft not liquid. The 5/8" hoses on the passenger side recover vapor. The 4mm line from the drivers side of the tank will push gasoline out on a hot day _________________ My father's 1970 Beetle-
http://www.thesamba.com/vw/forum/viewtopic.php?t=603879
The 1964...Diamond in the rough
http://www.thesamba.com/vw/forum/viewtopic.php?t=612776
My 1958 Morocco Bug-
http://www.thesamba.com/vw/forum/viewtopic.php?t=611483 |
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SpatzBuggy Samba Member
Joined: March 04, 2011 Posts: 5
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Posted: Fri Sep 19, 2014 4:58 pm Post subject: |
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Here is a drawing of what I am thinking I need to do.
If the basics are OK, what orientation should I use for the expansion tank?
Thanks |
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flyboy161 Samba Member
Joined: December 26, 2009 Posts: 2091 Location: Perry, GA
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SpatzBuggy Samba Member
Joined: March 04, 2011 Posts: 5
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Posted: Fri Sep 19, 2014 5:40 pm Post subject: |
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Flyboy,
Got it. Thanks!
I really appreciate the help.
Revised drawing look OK now?
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flyboy161 Samba Member
Joined: December 26, 2009 Posts: 2091 Location: Perry, GA
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