Discussion on evaporative system

[howew3]

Type 3 fuel evaporative control system

[Multi69s]

What do you want to discuss?
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69 road Bug 2110
73 Squareback - 2L, T4, Automatic W/ AC
Gone, but many fond memories 69 Baja Bug 2010 - 5 Rib Bus Transaxle
Gone but not forgotten 72 Baja Bug 2010
My builds
T4 into Squareback http://www.thesamba.com/vw/forum/viewtopic.php?t=458944&highlight=
Auto Trans Rebuild http://www.thesamba.com/vw/forum/viewtopic.php?t=516066&highlight=
AC in Squareback https://www.thesamba.com/vw/forum/viewtopic.php?t=...highlight=

[howew3]

Well I never paid to much attention to this. I smell gas at the front of the car under the hood. I looked up where all the hoses go the one I have missing is the one that goes from the fan to the canister in the rear. I do not have the original muffler system on it, a Bug Pack header system. So now how do I get air into the charcoal canister?

[Donnie strickland]

What year is your car?
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71 Elm Green FI A/T Squareback

[howew3]

1971 SB with fuel injection running good. The only thing not stock is the muffler system.

[Donnie strickland]

Here's a picture of my 1971 engine. See that open fitting at the lower left, on the "kidney" piece, just below the coil? There's supposed to be a hose there, which runs up the left side of the engine compartment, just ahead of the engine, to the charcoal canister. That supplies pressurized air to the canister, to force the fumes into the air cleaner to be burned. I don't use the charcoal canister any more, so I have plugged that port off. If you don't use the kidney pieces with your exhaust, you won't have this port.

The fumes from the gas tank travel through the fenderwell to the overflow tank under the left front fender. They then travel via a long tube to the charcoal canister, previously mentioned.

I was getting a gas smell after filling the tank, so last week I installed one of Jim Adney's fuel tank vent system replacement kits. I'll post some pictures later, but Jim's kit does away with the overflow tank/charcoal canister system.
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71 Elm Green FI A/T Squareback

[howew3]

Ya, that stuff was removed ffor the header muffler system.
Thanks for the info, have anice weekend Walt

[Donnie strickland]

I'll start with the rubber collar at the fuel fill. Mine was cracked and dried out, so I got a new one from ISP West.

You'll have to transfer your drain tube from the old collar to the new one. The tube has a lip on it, so you have to push it out to the inside of the collar.

While the collar is off, you can replace the overflow tube. Jim Adney sells a kit for this, which you can purchase by contacting him at [email protected].
After many years, this tube will eventually crack and leak, which lets water and dirt into your fuel tank, causing all sorts of problems. Mine was not yet leaking, but I wanted to go ahead and replace it:

Jim's kit includes a new Tygon tube, with Oetiker clamps, just like VW used originally:

And here's what it looks like installed -- part of the old tube is retained to act as a grommet:

On the inside, the overflow tube attaches to a tee:

After the new overflow is installed, it looks like this:

And then this:

On my car, there are two vent lines going across the trunk, and on early 1971's these lines are steel. Jim's kits include nylon replacement lines for these. Then there's the overflow tank under the left front fender:

Jim's kit eliminates the tank, and vents the tank fumes out the left front side of the trunk, as earlier cars did. The charcoal canister is bypassed completely.
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71 Elm Green FI A/T Squareback

[vwkombi1966]

wow donnie, that was really informative! i had always wondered how that system was SUPPOSED to work! i might even look into doing what you did, and bypass the canister too! thanx!
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Aircooled VW: more expensive than CRACK!

- 1968 Squareback (Scarlett)
- 1969 Westy

[Typ3nut]

Donnie,
Thanks for the detailed photos and info on this system as I will be referencing this tread to those that ask me about the "smell of gas" in their Type 3. I've been using J. Adney's kit for years without fail.

[Donnie strickland]

You're welcome -- Jim's kits are great!

I should add that I removed the overflow tank under the fender, as water and dirt tend to get trapped behind it and rust out that part of the body. Mine was still ok, but there was a little rust starting.

The evap system is something most folks don't know about, probably because some or all of it has been removed from many cars over the years. Mine was all there, but needed refreshing so I didn't smell gas inside the car any more. Also, if that overflow hose under the fender is leaking, water and dirt can get into the tank and rust it out from the inside, not to mention ruining the rest of the fuel system. It's a simple fix with this kit, for about $30, instructions included.
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71 Elm Green FI A/T Squareback

[jaworskin]

I am not smelling gas inside my SB, I smell it in y garage when I park it. And it is string. Will this solve that problem as well?

[KTPhil]

With a fuel leak/smell, you have to check everything point by point, for safety's sake.

A common leak point is at the tank end of the large filler hose. That is actually submerged with a full tank. There is a thin rubber sleeve at each end of the thick hose that can leak. ISPwest sells them. Also, your gas gauge sender can leak.

And of course you need to check all your lines under the tank.

[artcfartc]

Are Jim Adney's kits still available? If so, please let me know how to get one. Thanks!

[artcfartc]

Sorry, found my answer in the thread after logging in on my desktop. I sent an email to Jim and heard back. He is still making the kits. Email is [email protected]

[Bobnotch]

[blues90]

I got the collar from ISP since the original was dried out and cracked. I got the new collar on yet I can't get the retaining ring in the new collar. What's the trick ? I still had the original ring I saved it.

[blues90]

I replaced my collar with the ISP one, What's the trick to install the retaining ring in the collar?

[KTPhil]

IIRC, it was easier to add the ring before pushing it on to the body.

[blues90]

I tried that , it was hard enough to get the ring in the cups groove then it popped out trying to install the collar. I tried both ways. right now I just got the collar in and rotated it a bit so the collars lip seated in the fender hole. Trying to just push it in to get the lip seated didn't work it kept popping out , rotating it was the only way that lip would seat.