Fuel Vapor Canister Needed, 1970 C10

[mosel70]

I have a CA 1970 Chevy C10 with the original 402 engine. The truck has an EEC fuel tank behind the seat. I've looked all over the web and can't find a fuel vapor canister or instructions on how to hook it to the engine. Anyone got any ideas or resources?

[71CHEVYSHORTBED402]

Here's some info., though it's for my 1971 402. I don't know if a 70 differs, but I'm guessing not:

Vapor canister bracket mounting: The vapor canister bracket mounts using the same screws for mounting the RH (TS) fender to the gusset.

Vapor canister belt: The belt mounts the canister to the bracket using two 7/16" head tapered screws with integrated washers. The screw threads are 1/4" x 1/2" & 20 TC. Correct positioning of the canister is the valve ports face the rear (TS).

See: https://www.youtube.com/watch?v=8HmiBp9ibfU

Original canisters for 1971: 7028129 or 7030541: The canister on my truck was 7030541.

GM replacement canister: 7030605

Another replacement that works: 17063011. The "Carb Bowl" is sealed on at least some of these canisters. The Carb Bowl is not used for a 1971 Chevy truck.

Other:

Filter: 7026014

Standard filter: 729150. This element is pretty stiff.

Funnel with pad: 7021739. Some canisters may have come with the bottom “funnel cover", though mine didn’t have one. The funnel just snaps into place. If a funnel is used, then the filter can be placed inside that or in the underside of the canister. Found these instructions online: "Install new filter assembly by aligning the slot in the cross bars with the single crossbar on the bottom of canister, and snap into place".

Funnel with pad: AF-450:

Note: Two thin pieces of foam rubber are located inside the canister, one at the top and the other at the bottom. The bottom often has holes in it from wear, which causes the charcoal to leak. Contrary to popular belief, DO NOT shake the canister to see if the charcoal is good. If it’s loose then then it likely is leaking through the bottom foam rubber. Shaking these just contributes to the damage.

http://www.docrebuild.com/dr-r-web/PCV1.PDF

[71CHEVYSHORTBED402]

Course you don't have to use a canister. What configuration is necessary for that is beyond me, though I believe a two-way vented cap is necessary.

My truck didn't have the canister either. At one point the line that would otherwise be to the canister had a filter on it. I haven't been able to locate that (ha!) and figure to confirm when the body is off the frame. I can say I've got two fuel lines from the fuel tank and pump. I believe one is a return line.

Not to hijack your thread, but on topic for sure, it would make my day if someone could correct/confirm that for a EEC system (i.e., vapor canister) the correct configuration should be:

1. One-way "vented" cap. One-way being air intake, so it's a really vacuum. It doesn't release vapors.

1A. How can you confirm you're buying/using the right cap? In other terms, what's a cap with a one-way "vacuum" called? Perhaps I'm missing the point.

1.B. Assume you have the canister and a two-way gas cap (vented & vacuum). Probably works right? Course that might defeat some purpose of the canister.

2. If a canister is used, I'm pretty sure you don't have a return line between the fuel tank and pump. In other words, there's one line between the pump and fuel tank.


BTW OP, good luck finding an original canister that doesn't leak through the bottom foam rubber element. I can tell you where to cut the canister open if interested. I can also say that if it's a slow leak, a temporary solution is the Standard filter: 729150. It's fairly stiff, so basically the charcoal is captured by the filter. Not quite as intended, but my GUESS is it works well enough.

On topic of canisters, why on earth isn't there an aftermarket, considering GM used nearly the same canisters for all classic vehicles? There's some cash to be made out there. Can't be that difficult to build a canister.

[mosel70]

Now that was one great response! Thanks!! I finally found a canister ('71) on Ebay with the mounting bracket, very hard to find. So yes, I would love to know how to open the canister and replace the charcoal filter.

[71CHEVYSHORTBED402]

Originally Posted by mosel70

Now that was one great response! Thanks!! I finally found a canister ('71) on Ebay with the mounting bracket, very hard to find. So yes, I would love to know how to open the canister and replace the charcoal filter.

Nice find on both.

The filter is easy, you just need to buy one. Incidentally, the Standard filter 729150 I mentioned above that's stiff? Well, it depends. The white one is stiff. I don't see any of these on the web right now, but the regular ones are available.

As for cutting one open, first post per the following link tells you where to cut one open.
http://67-72chevytrucks.com/vboard/s...d.php?t=686040

I used a Dremel, but that was a "test run". When I do it for reals I'll use something like this. https://www.amazon.com/IVY-Classic-3...+plastic+blade

As for the rubber foam elements inside the canister, once you see one you'll have an idea what to buy. Perhaps a pet store, same place you can get charcoal.

I hear an epoxy is how to reseal it. I haven't done this yet.