Complete Fuel Tank Venting / EVAP System Walk-through

[AlmostHeavenWV_VW]

DO NOT WELD GALVANIZED STEEL

The evaporation of the galvanizing WILL make you ill, or worse
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1973 Standard Beetle
1600DP AK case
Solex 34PICT3 Carb
Bosch DVDA 205AJ Distributor

[MuzzcoVW]

[busdaddy]

JB weld would be a more suitable product there, it doesn't get hot enough to need to be welded.
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Rust NEVER sleeps and stock never goes out of style.

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[scarruth]

This is awesome. Have a '73 Type 181. Expansion Tank and Canister intact. Scratching head on how the chassis lines attach. Clips missing. Parts Manual has no information. Use break line clips maybe with the chassis bolts?

[Tim Donahoe]

The line that goes under the right side chassis isn’t heavy. You could fabricate almost any sheet metal to function and attach with the carriage bolts. I’ve seen a number of Samba Classified ads where the OEM brackets are for sale.

Tim
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Let's do the Time Warp again!

Richard O'Brien

[Maltboy!]

[chicagovw]

My car has a bad fuel smell in the trunk and as a result, the passenger compartment. My nose tells me it is from a crack in the expansion chamber, so I am planning to get a replacement.

However, much of the rest of my system is long gone. I would not have an issue of replacing it all, but I have a 1914 cc engine with dual carbs, a different fan shroud etc. Would it help to simply vent the tank using the older pre 68 style of a hose with trap vented to the atmosphere ( my car is a '73 super)?

[vamram]

[chicagovw]

The cap seal is in good condition. The smell seems quite strong near the left side of the vapor chamber, and I can see that it was repaired there at one point in time. I do not mind putting the time and effort into putting the system back in working order, just did not think it could be done with the non stock air cleaners and fan shroud.

[Weezle]

I have reinstalled my evap system in my car which has a DTM shroud (no pressurized nipple) and dual carbs. You can buy for just over $30 the water cooled version of the charcoal container for the right rear wheelwell. It doesn't attach to the shroud like air cooled, the top connector is kind of a trumpet open to atmosphere. the lower end has the evap line from the tank going in and also has the 12mm hose to the air cleaner. I just put a small plate of metal with the appropriate nipple on the back edge of my air cleaner and plugged the hose in there. I have minimal (and usually no) gas smell in my garage. or in the car. prior to rebuilding the evap system my entire garage smelled like a filling station. there should be a pic or two in my build thread, second link in my signature.
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I got a fever, and the only prescription is more beetles!

http://www.thesamba.com/vw/forum/viewtopic.php?t=604918&postdays=0&postorder=asc&start=0

https://www.thesamba.com/vw/forum/viewtopic.php?t=759868&highlight=

[OldPrinter89]

On my ‘72 super I’m following the evap lines around the trunk.
There’s a white plastic line that travels across the cowl, then I think it should go
Down under the car.
That line is MIA, how do I route a new line down and out?
Can’t really figure out how it should get out.

[AlmostHeavenWV_VW]

[OldPrinter89]

Thanks, I’ll dig around some more. Surely someone didn’t remove the metal line. Also my expansion tank is MIA, but the lines appear to bypass it and are intact.

[EVfun]

[AlmostHeavenWV_VW]

[Lost69Convertible]

A non-automotive name for the expansion tank is GLS: Gas Liquid Separator
(Here “Gas” is a gaseous state. Not gasoline)

On the drivers side, I think Line 4 is for gaseous and liquid phases of gasoline to expand (or burp) into the GLS. And I think Line 5 is for liquid to drain back to the tank - but this line probably burps into the GLS at times.

On the passengers side, I find it hard to tell what the real intention is. But I agree there must be a drain back to the tank on the passenger side. The car and GLS can roll to both sides - so a liquid drain on both sides is needed.
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1956 Beetle Ragtop: My Father's car
1969 Beetle Convertible: My first car. I loved it, I lost it, and I never got over it.
1979 Super Beetle Convertible

[tissyfit]

I will be utilizing this page in the near future amazing tutorial.
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New at this vw stuff. Any knowledge is helpful knowledge is power!

[2002EVC]

Finally diagnosed that my expansion chamber / fuel trap was plugged after getting pressure from the cap as well as leaking at the filler connection. Instead of finding a replacement '71 SB expansion trap, I connected two separate 5MM lines as shown as 5 so that any expansion fuel drains back into the tank and 4 attaches to 6 to the right corner of the car. On a hot day I get some condensation to the right rear, but it seems to be working with no fuel smell.

The original expansion trap is not cracked, just seems clogged. Any ideas on repairing or if that's even possible? When I blew air into it, it was clearly restricted, but I figured I'd ask here about how to clean that or if it's even possible.

[DUNGBTL]

I made my own vapor trap…

[Lblossom]

I finally have the official VW manual which explains the emission control. Reading that is fine but this thread has my brain spinning. I am attaching a photo that shows that here is not an expansion chamber but shows the hoses. The carbon canister is gone leaving only the bracket. After replacing the plastic hose from the evap tube which had become hard and broke at the point where it attached to the small metal tube, and leaving it open to vent ( I think i understand why it was attached to a metal fitting that was closed at the end which with the original set up made sense) I still have some gas odor. I suppose I should look for another open hose or tube somewhere? Maybe replace the evap tube? Is it available…I’ll ask at bugcity.com/. This is a 71 super beetle. Any idea what replaced the expansion chamber? Thanks. There really are not people in my area who work on these cars although one person with very limited time helps with the engine. Upstate NY beetles have rusted and were gone decades ago.