Two-port Fuel Vapor Canister Recharge/Refurbish

[69hurstolds]

Ok, I've decided to take my old canister out of the 85 442 and redo it. Not because it was bad, per se, but because if I screw it up, I got new ones stashed away so I've got a back-up plan. And since others have actually done this, it's something I've never done so it's on my "bucket" list of sorts.

Easy peasy to get it out. First, remove the 2 hoses that attach at the top nipples. Boom. Then, using a long extension and a 10mm socket, I used my electric ratchet to make quick work out of those little screws holding the canister down to the fenderwell. Lifts right out.

Then, clean the canister by wiping it down or whatever. It gets real dirty on the bottom, especially if you've never had it out before, like me.

Turn it over, find the replaceable filter. Just pinch it with your fingers and remove.

Here's where it sits.

Remove the clips with a small screwdriver or other tool.

Then inspect the bottom carbon bits retainer foam. Hmmm. This one looks like it was on its way out anyway. Note the cracks. Not good.

Now you can start trimming the little plastic bead left from the plastic "welding" done at the factory. This usually will leave you with a small seam area you can see. But it's nice and smooth around the bottom now.

The knife bit was getting tedious. I broke out my old battery powered Dremel. But wouldn't you know, the batteries were weak. I tried charging them like, forever, and they lasted for about 30 seconds after 3 hours on the charge.

Enough for today. I decided to disassemble the battery pack for the Dremel and found 6 of the 1.2V, 700mah AA NiCd batteries inside. Crap. Just happen to have some 1000 mah AA NiMH batteries for the wife's solar light thingies. Hmm.

So I spent the afternoon working on making a battery pack for the Dremel with the NiMH batteries. Just got it done and it works like a champ! But not going to rip into the canister this evening. I'll save that for another day. The wife just had some day surgery yesterday for a small procedure, so I've been bouncing back and forth taking care of her and trying to be quiet letting her rest. I got some carbon coming from the fish store, and I have a handful of canister replaceable filters on hand already, so we'll see what happens shortly.

More to follow...

 

[69hurstolds]

Ha. Never noticed it has a manufacturing date code on it as well. 02951, or 29th day of '85, (Janurary 29, 1985) 1st shift. Makes sense as mine was built in February 85.

 

[69hurstolds]

Ok, went back to work on that bad dad with a new set of batteries for the Dremel. I could have got out my electric dremel but it's got a flex cable on it and hangs off a pole at the work bench. PITA to deal with all that there. This is a quick job I can do out on the deck in the sun and this little battery Dremel works just fine for what I need to do.

The dremel cut off wheels are fairly thin, about 1/16" of an inch thick. Made fairly quick work out of cutting the seam all around the base. Hi speed worked best. It did some cutting and a bit of melting, but the goobers were super easy to trim off. About 10 minutes around the horn approx 1/8" deep groove right above the seam and that seemed to do the trick. All that juking around with the canister though caused the cracks in the lower retainer foam to open wider and a few granules started to come out. I stopped about 1/2 way around and poked the foam here and there with a tiny screwdriver and poured out all the carbon chunkies into a container, which I had already tared on my postal scale.

NOTE: I wrote this before I realized not all carbon is the same. It varies by brand, type, and source material. Density matters so you can't just go by a standard weight. Everything is by volume. See a later post where I get into that.

Net weight ~19.2 oz. of granulated carbon chunkies. I say approx. because again, this ain't no science. But if you just buy a pound of granules, you'll be about 3.2 oz. short. Best to buy 3 lbs of pellets, or if you can buy a 40 oz. bag of granules somewhere and you are set.

The bottom foam near the replaceable filter is 1/8" 1/4" thick. The top foam carbon retainer is 1/4" thick. The top foam was in great condition still. Nice and spongy. The bottom? Eh, you know that one was dried and crumbly. Left alone at some point you would hit a pothole and possibly jar the filter loose and lose all the granules.

The diameter of the foam retainers both are 4.75". So just in case you're going to make some. I don't even know if they make them that size. Regardless, I think I'm going to get something like a man-made polyester fiber filter, or something similar, if I can find something suitable. Or I might just get some more foam, not sure yet. If it lasts another 39 years, it'll outlast me.

Bottom cut off. I poked holes in the deteriorated foam and simply poured out the carbon granules. Retainer simply sits inside. It simply rests on the supporting "ribs" on the inner diameter walls of the canister.

Little hook tool pulls it right out.

Looking inside after the lower retainer is out (see the ribs here on the walls for holding the lower retainer in the right place) you can see the upper retainer foam. Just reach in and grab that rascal. Normally you might see just some carbon chunks here and there, but when I was pulling out the lower retainer crusty foam chunks fell down.

Upper foam removed. Tank vent enters in through the center. Port hole on the left is the one going to the carb, and the port hole to the right is the "dummy" connection that goes nowhere. You may can do something with the top of the unit, but this is as far as I'm going with it. There's really nothing left here to do.

Upper retainer foam on the left, and lower foam retainer on the right. You can see some of the dead lower foam on the retainer. Gonna take a little scrubbing but it should clean up well.

That's it for today. Carbon bits will be here tomorrow. Now I'm going to research the foam retainer substance and see what I can come up with.

The carbon bits I'm getting are more like pellets that granules. Which is fine by me. I know the surface area won't be as good as granules, but if fish can deal with it, so can I. Again, this will probably outlast me if I can finish this project without screwing it up too badly.

 

[69hurstolds]

Thinking more about the bottom filter foam...I'm believing it also USED to be 1/4" thick as well. Just that over the years, the weight of the granules crushed it down to about 1/8". Can't imagine that they'd use half the thickness of the upper foam retainer for holding up the weight of the granules like that. The original that flaked away had no flexibility nor rebound as crusty as it was. Thinking more along the lines of 1/4", 30ppi speaker foam...we shall see.

 

[84 W40]

Ha. Never noticed it has a manufacturing date code on it as well. 02951, or 29th day of '85, (Janurary 29, 1985) 1st shift. Makes sense as mine was built in February 85.

I wonder when GM started date coding the canister, don't remember seeing one on mine but was not looking for it either.

How thick is the plastic you were cutting? Just thinking if a oil filter cutting tool would work, they do come in different sizes and not expensive.

 

[69hurstolds]

Didn't measure, but the plastic appears to be about 3/32" give or take. I'll measure it. It MIGHT work, but my Dremel was already here. Might make a neater cut. I wouldn't have made a good surgeon. I lost many an "operation" game.

 

[84 W40]

That game was rigged right out the box, it wasn't you.
A good place for speaker foam is Parts Express. I have used them restoring my tower speakers.

 

[69hurstolds]

That game was rigged right out the box, it wasn't you.
A good place for speaker foam is Parts Express. I have used them restoring my tower speakers.

Hmm. I searched Parts Express and got 3/8" thick foam results. Other than that, it was insulating foam.

Ended up buying a roll of 1/4", 30ppi foam from The Foam Factory. Part of applications list shows it's good for filtration and coalescing gasoline from water. So I'm expecting it to hold up with gas vapors. 72 x 48 sheet of it. Delivered for $28. Fingers crossed. I'll likely have extra.

 

[rfpowerdude]

...I'll likely have extra.

 

[69hurstolds]

I've got this sneaky suspicion that the material is polypropylene or polyethylene. Which means that black plastic weld epoxy stuff I originally intended on using MIGHT not work. I don't know, because I'm not fluent in identifying plastics just by looking at them, but polyethylene is used a lot on gas containers and those car plastic gas tanks, so it wouldn't surprise me that the canister isn't made of the same stuff. It's hard to glue so that's why they used the plastic welding routine on the cans. Just my suspicion, no proof.

Thus, rather than mess around with all that, I think I will try this stuff first. It's a two-part bonding superglue type agent that's supposed to work on poly plastics, so we'll see. A $5 experiment and it's local to pick up anyway.

Also, got the replaceable filter ready for action. ACDelco/GM part number A478C or 7026014. Even the packaging screams "OG". Just dirty on the outside, though.

Cheap, activated carbon pellets. Not as much surface area as granules, but I'm sure it will do what I want it to do and still be large enough not to easily fall through the slightest little crack should that happen again.

Now it's just wating on the foam to arrive and I'll get back at it.