Thingy below vacuum tank

Mad4slalom

CCCUK Member
Hi all, had the 72 on the lift today for an oil change and a chassis wipe down as I got caught out on a wet road Again😤 I was under neath and saw a cylindrical container below the vacuum tank . Is this a charcoal canister? Any ideas appreciated. Just that there are two thin pipes coming off it that looks like they have been capped with two small bits of rag and a cable tie . 👍TiA
 

TimP

CCCUK Member
If it is what I think it is then it's a dryer but filled with cotton/material wadding rather than carbon. Is it about 6 inches in diameter, 6 inches high held on to the area just above the driver side gill by two circular bands? I think I have a photo somewhere...
 

TimP

CCCUK Member
Is it this?
Engine Bay 22.jpg

Trying to find it on a circuit diagram but can't find anything at the moment - it might take a while to find the right picture, but I'll post anything useful that comes up.
 

TimP

CCCUK Member
.... and shown on UPC LT1 Sheet B2 of the 72 Factory Assembly Manual if you have it. let me know if you haven't got it and I'll send you a pic. On my car the bottom cover easily comes off to reveal the contents.
 

teamzr1

Supporting vendor
If EVAP tank,
it comes apart as there is a filter inside that needs to be replaced either every 2 years or 24,000 miles, whichever come first
 

teamzr1

Supporting vendor
Really surprised how many C3 owners never think of changing the EVAP filter causing odd rich conditions as the fuel fumes not being able to be vented out
GM says to replace either every 2 years or 24,000 miles, whichever comes first

 
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CaptainK

CCCUK Member
I must confess I didn't know about this on my C3. So I looked it up on the internet.... and it seems my 1968 doesn't have one as apparently they were introduced in 1970.
 

Chuffer

CCCUK regional rep
I recall reading somewhere a while back that you can disconnect them but you would need to then have a vented fuel tank filler cap .
 

TimP

CCCUK Member
There are three connections on the top of the canister.
The larger one on its own on goes via a short hose to a pipe that goes along the drivers side chassis rail to the fuel tank (UPC8 sheet B6 in the FAM), one of the two on the raised area goes to a 'T' the top of the drivers side rocker cover, the third goes to a nozzle on the front of the carburettor (UPC8 sheet B7).

There is also one connection on the bottom of the canister but I think that is a drain.
 
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