fume venting

[chitwnvw]

Trying to straighten out my venting in the engine compartment.

Where's the orange vent tube supposed to go to?


Also got this plug hanging down, anyoneknow what it was for?



And need to run the breather hose to the air filter, anyone know what this boss on my Weber's air filter, was thinking of using it, there's a plastic cap on it and then some rubber stuff filling the hole up...

[Sluggo]

Both vent lines (they are the fuel tank breather lines) should go into the small nipple on your charcoal cannister. On this same side, the large nipple would go to your fan shroud. The large nipple on the opposite side would go to your air intakes. Your Oil Breather should also vent to the air intake. I would guess is what that nub on your air intake is for.

The plug is for diagnostics. No one has the analyzer anymore. Tuck it away and forget about it.

By the way, I got the PHP book. THANKS! It should be a big help.

[spiffy]

http://www.ratwell.com/technical/VacuumHoses.html

This may help you out a bit.

[chitwnvw]

Thanks, I think your explanations were pretty clear.

Does anyone know do these charcoal canisters last forever, or were they supposed to be replaced now and again ( not that we have much choice ).

[Sluggo]

Thanks, I think your explanations were pretty clear.

Does anyone know do these charcoal canisters last forever, or were they supposed to be replaced now and again ( not that we have much choice ).

There is a way to replace the charcoal. And it is recommended. I can't remember where I saw it. I was told that if you can blow and suck easily through the cannister it should be okay.

[chitwnvw]

So the charcoal expands as it absorbs the bad stuff?

[Sluggo]

I'm not sure. There is probably a write up about it on Ratwell's site.

[Amskeptic]

So the charcoal expands as it absorbs the bad stuff?

Charcoal has amazing absorption properties. It does not change size.
You can use aquarium charcoal trapped in mesh to replace your missing charge. Earlier metal canisters are harder to recharge.
I have never touched mine, it breathes, good 'nuff.
Colin

[Sluggo]

You can use aquarium charcoal trapped in mesh to replace your missing charge. Earlier metal canisters are harder to recharge.
I have never touched mine, it breathes, good 'nuff.
Colin

Good to know. I looked around and can't find that page I saw on how to do this. Maybe something else to add to my how to section.

[Bookwus]

Hiya Sluggo,

I think I'm the one who originated the write-up on "refreshing" the charcoal canister in the M-26 evaporative emissions system. After reading many posts asking if the canisters were necessary or (if they were) could they be refilled, I decided to give rebuilding one a shot a few years ago. VW originally recommended that these canisters be replaced every 40,000 miles. And while they do still offer a replacement (albeit a superceded part which has little physical resemblance to the original), it is much cheaper to go the refill route.

Interestingly, after prolonged usage the charcoal becomes a single mass. This seems to be due to the accumulated crud and moisture which is trapped in the canister. In any event, as this condition worsens with time and use it becomes progressively more difficult for the cooling fan to force air through the canister. This leads to system failure for the M-26, which, in turn, leads to loose hydrocarbons with no place to go. Not a particularly desireable situation.

Here's my original write-up................

Do keep in mind that the following information is good for the metal emissions canisters used in the early seventies.
"Insofar as the charcoal canister (E-Can) goes..........do know that one should be able to blow through it without any restriction. To test it, simply pull (disconnect all the hoses) the canister out of the system and blow through larger opening on the end with two openings. If resistance is felt or its completely plugged (and many are) it's time to clean.
To clean it out one will need to refill the canister. So..........drill a 1.5 inch hole 1.5 inches in from the end with the two openings. Once that is done you'll see the carbon (charcoal) pellets. They'll probably need to poked around a bit to loosen them. I used a dull screwdriver - worked great. Once all the carbon is out take a look inside. Look for a golden color. I believe the inside was anodized. If there is a lot of rust or unremovable crud inside, think about getting a new canister (more about that later). Any light dirt can be rinsed out with a light solvent. I'd recommend a water based cleaner such as Simple Green. Just pour about a half pint in and do the shake around thing for a couple of minutes, then drain.
Do not remove the internal "pads" at either end of the canister. The solvent should do a good job of rinsing them out. However, without the charcoal in the canister the springs (2 of 'em) behind the end pad will want to come out. I fumbled around with them for quite a while trying to get them back into position behind the pad. Fool's errand. I finally just wound up "unscrewing" them through the 1.5 inch hole I had drilled in the canister wall. In any event, when it is all dried up refill with new carbon. Be sure to get pelletized carbon which is available at any good pet/fish/aquarium store. I found Coralife packaged in a half gallon container. The refill will require two of these. The canister will take just a little more than a half gallon of the pellets. I got it for $6.95 for a half gallon container. This stuff is identical to the "original load".
Seal that 1.5 inch hole any way you think best as long as it is airtight. Me? I soldered in a screw cap fitting (I think I used one from an old can of Thompson's Water Seal). This way I can unscrew the cap and change the carbon in the future with no big hassle. Reinstall the canister and you are on your way.
Total time spent on the project (assuming the parts and tools you'll need are at hand) was less than one hour. An easy weekend project to get no more gas smell and a less polluting vehicle. And a lot less costly than buying a new canister (continue for more on that).
Oh yes.......about finding a new canister. They are available for cheap at a most VW oriented wrecking yards. I would not pay over $5.00 for one and most I have bought have been in the $1 or $2 range. If you can get into the yard yourself (like a Pick-a-Part kinda yard) look for an E-Can from a Porsche 914. It's the exact same E-Can (113 201 801A) as used in Bugs and Busses (70-74, I think) and its located in the front trunk. It is protected from the elements and will be in much better shape than one from a Bus or Bug.
So........don't want to go the refill route? You'd rather have a brand new shiny canister right off the shelf. You can go this way, but there are two important factors to be considered when making this choice.
First of all, the part now available (175 201 801A) is a superceeded part. That means that the part may not confirm to the original physical specifications of the OEM part but will function in the same manner. This is true of the "175" emissions canister. The "175" is made from plastic components and is cylindrical in shape. At approximately 13 inches in length it is a poor fit for either the Bug or Bus. However one can get it to fit with some "creative engineering".
Then too there is the issue of cost. The "175" will cost you about $65US. The cost is hard to pin down exactly because of the dealer's mark-up. I have seen them for as low as $57 and as high as $71. It is available at your local VW dealer. He will have to order it from a regional warehouse so allow for a few days for delivery."

I hope that helps out some fellow bus pilot who might be considering alternatives to the canister situation on his or her own bus.

Mike

1970 Bus - The Ruptured Duck