More vapor canister stuff - Cut one open and observations.

[71CHEVYSHORTBED402]

I have three canisters, and cut the bad one (battery acid) open with a Dremel, for practice. That and to see what's inside. Edit, note it seems better to cut the canister at the bottom seam, not the can's top

First, I errored trying to cut it open in the area slightly below the seam just below the top. That's not where you want to be. You run the risk of cutting the foam element, air stubs or even the top inside the canister. To do it over again, I'd either:

Cut 5/16" below that seam to save the element.

Cut 3/8" below that seam, knowing the foam element may be damaged, but miss the air stubs.

Cut 1/4" below that seam, cutting into foam element. If you cut much deeper than you have to, then you may damage some air stubs.

Ever hear "if the charcoal doesn't move when you shake the canister then it's bad"? I call BS. More than likely it means it's leaking through the foam at the bottom. The one I cut open had no movement inside, but the charcoal looks like it had just been added. No discoloration, nothing. Just packed tight and hadn't started leaking yet. It should be noted, there was 100K on this canister. Additionally, I've got two beautiful canisters, and the charcoal is loose in each one. Go figure, both leak charcoal from the bottom through the foam. My recommendation is don't shake them, it's not going to help your cause.

There are three foam elements inside these canisters. Possibly polyurethane "filter foam". There are two on top, and the one bastard on the bottom. These are about 1/8" thick (See image below). I'm not aware of a substitute for this (anyone?), but you can make do. The bottom one obviously goes bad from the weight of the charcoal. Good read here: http://www.ifsja.org/forums/vb/showthread.php?t=174213

Speak of leaking, I located an interesting replacement part for the filter you can access underneath. It's much more rigid than the common filters, which are like fiberglass insulation. I think I'll choose the best of the two, seal the foam rubber where it's leaking, and just as a precaution, use the rigid filter to catch any charcoal that may leak in the future. This way I don't have to rebuild one, at least not right now.