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Mounting charcoal canister [message #282106] Tue, 14 July 2015 16:25 Go to next message
habbyguy is currently offline  habbyguy   United States
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Location: Mesa, AZ
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Wow... I was tackling some projects on the coach yesterday and this one is the last one I expected to give me any problems (or cut up, bruised arms...).

I got the clamp loose, and expected to be able to just pull the canister up and out... errrr, no. Fighting with it for an hour netted no movement, and the bolts that hold the cylindrical mount in place are blind, with some sort of interference lock nut, so they just spun (and spun, and spun). Eventually I got caveman on the whole thing and just cranked on the mount until the whole thing came out, having ripped the sheet metal around the blind mounting bolts at the bottom of the housing.

Now, with this thing sitting on my garage floor, you'd expect that it would be a simple matter to extract the charcoal canister, wouldn't you? I sure did. And I was wrong, wrong, wrong. I ended up having to take the thing out in pieces to get it loose. Sure, there was a bit of rust inside the mount that might be trying to hang onto the canister, but it didn't make any sense at all that it would be THAT tight. After breaking it to pieces to get it out, I tried to push the replacement canister in, and realized that there's a molding lip on the bottom of the thing that would result in the same fit (and the same problems next time I wanted to remove it). Both of the canisters were the new aftermarket variety (probably the one you'd get from any of the GMC vendors).

Obviously, someone didn't do their homework on this, or the part would fit loosely enough in the cylindrical mount that only the clamp would hold it in place - that would be more than necessary. Whoever mounted the old one no doubt just jammed it home in the housing, guaranteeing that it would never come back out in one piece.

In the end, I just left the mount out, and bungee'd the canister in place on the flat panel the mount is normally bolted to. That should be more than adequate to keep it in place, and will save me loads of time (and aggravation!!!) next time I need to change the canister (hopefully, never).


Mark Hickey Mesa, AZ 1978 Royale Center Kitchen
Re: Mounting charcoal canister [message #282128 is a reply to message #282106] Tue, 14 July 2015 20:25 Go to previous messageGo to next message
jhbridges is currently offline  jhbridges   United States
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mine has two canisters in series, each in a sheet metal clamp with two long bolts through the tabs, and the rear of the clamp bolted to the firewall (upper) and a frame crosspiece (lower). I took the wheel and line roof (well actually already had them off for something else) and backed the bolts out of the tabs with a wrench and a ratchet. I had to spread the clamps to make them let go of the plastic canisters, but they're thin and bend back easily. And easily bent back into place to replace them. Snugged up the nuts and done. It was harder to get the new hose on the tank vent line than to get the canisters out.

--johnny


Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons. Braselton, Ga. I forgive them all, save those who hurt the dogs. They must answer to me in hell
Re: Mounting charcoal canister [message #282132 is a reply to message #282106] Tue, 14 July 2015 21:01 Go to previous messageGo to next message
Ken Burton is currently offline  Ken Burton   United States
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I would be worried about the bungee cords rotting out over time and the canisters falling out on the road.

Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
Re: Mounting charcoal canister [message #282134 is a reply to message #282106] Tue, 14 July 2015 21:50 Go to previous messageGo to next message
habbyguy is currently offline  habbyguy   United States
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I can only guess that the original canister is small enough to just slip into the cylindrical housing, and is then held in place with (only) the clamp. The "improved" model's lower "lip" is what causes all the grief... it's just too big to go in, and because of how thin the "lip" is, it deforms and forms something akin to the barb in a fishhook, making certain that the canister will NEVER come out (even when you want it to).

And yes, I will have to keep an eye on that bungee, but I'll also probably work out some other option (I'm thinking a coffee can bolted in place might work well, or maybe I'll just epoxy a big honkin' magnet on the bottom of the canister... ANYTHING is better than having to do what I did this time to take the canister out.


Mark Hickey Mesa, AZ 1978 Royale Center Kitchen
Re: Mounting charcoal canister [message #282135 is a reply to message #282106] Tue, 14 July 2015 22:19 Go to previous messageGo to next message
John Heslinga   Canada
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Registered: February 2011
Location: Edmonton, Alberta, Canada
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Mark. If your catching the little bumps on the bottom of the canister bracket the xanister is going in too far. Those bumps are what the canister sits on. To keep it from bottoming and sealing off the 1 inch hole in the bracket. I'll upload a picture tonight. I found that by removing the bracket and canister as one and then removing the canister was fastest and easiest.

John and Cathie Heslinga 1974 Canyonlands 260 455, Manny tranny and 1 ton, 3:70 LS, Red Seal Journeyman, DTE, BEd. MEd. Edmonton, Alberta
Re: Mounting charcoal canister [message #282138 is a reply to message #282106] Tue, 14 July 2015 22:47 Go to previous messageGo to next message
habbyguy is currently offline  habbyguy   United States
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Registered: May 2012
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Hi, John... The problem isn't the bottom of the canister, it's that the outside diameter of the lip around the bottom of the cannister is bigger than the cylindrical mount, so you have to really lean on it to get it in, then there's no chance that you'll ever get it out again, particularly if you add in some rust, dirt and debris. I'd have loved to at least been able to remove the bolts holding the bracket in place, but they were blind bolts (with the heads under the canister), so they just spun.

The more I think about an epoxied magnet, the more I'm liking the idea - just rip one off a junk speaker, put a big blob of epoxy on it, and sit the canister on top of it. Sit it on the frame rail (or on the flat area the bracket used to bolt to), and it's never, ever gonna go anywhere until you want it to.

FYI, here's a link to a photo of a similar canister - you can see the same kind of "lip" at the bottom - if that wasn't there, it might just slip into (and more importantly, out of...) the bracket.

http://www.autosparepartsmart.com/images/emission_parts/vapor_canister_cp1022_buick_olds_gmc_chevy_p_n_77_95_b.jpg


Mark Hickey Mesa, AZ 1978 Royale Center Kitchen

[Updated on: Tue, 14 July 2015 22:50]

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Re: Mounting charcoal canister [message #282144 is a reply to message #282106] Wed, 15 July 2015 00:30 Go to previous message
John Heslinga   Canada
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Registered: February 2011
Location: Edmonton, Alberta, Canada
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OK :: That can be a problem. The bottom ofthe canister is "Spun Welded" and will leave a lip (Flash). That Lip will catch behind the bracket fingers once they have been clamped, or jam in the lower part of the bracket as you have noted and seen here.

http://www.gmcmhphotos.com/photos/carbon-or-vapor-canister/p58489-can-brack-7.html

I'm pretty sure you can file the welding flash off flush with the canister and that should improve the problems you are having. As you can see in this picture those bolts that hold the Can to the bracket will slip and are impossible to get off if you have no access to them. That's why I remove the bracket from the frame. Those bolts are self threading and a little easier to access. (leave the hoses on because the nipples wil break easy at this stage of the game. The canister should only be inserted so it rests on the "saddles" molded into the can.
http://www.gmcmhphotos.com/photos/carbon-or-vapor-canister/p58484-can-brack-1.html
http://www.gmcmhphotos.com/photos/carbon-or-vapor-canister/p58485-can-brack-2.html
http://www.gmcmhphotos.com/photos/carbon-or-vapor-canister/p58487-can-brack-5.html


I have way more information on the canaister is the entire Album that there pictures are located if you are interested.

All of that being said however. Which ever way you get that canister to stay in place is OK because it really does not matter except that it has to actually hold the canister in place. GM used a lot of different stratigies to mount the canister. Unfortunatly in the frame position it is in is very dirty because of the front wheel kicking up dirt. so the can on the end of the canister helps to keep dirt out.

Good Luck !! and have a great day.



John and Cathie Heslinga 1974 Canyonlands 260 455, Manny tranny and 1 ton, 3:70 LS, Red Seal Journeyman, DTE, BEd. MEd. Edmonton, Alberta
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