Charcoal Canisters

[Chris & Ranae Procyk <procyk19@domain.elided>]

I've seen two types (All vehicles, not just IH)

The basic theory is that the charcoal sucks up raw gas fumes, and then the motor sucks them back out of the charcoal and burns them.

Early and recent:
-This has one line from the fuel tank, and two that terminate at varying places.  The fuel tank line is where the fumes come from.  The larger of the two lines is where the fumes get sucked out from.  Finally, there's a "purge" line, just a vacuum control line.  Fumes are only sucked out when this line has high vacuum.  Therefore, you aren't sucking this stuff out except when you aren't asking your engine for power.
And if the filter's clogged, as was said, it probably doesn't do much at all.

Mid '70's to '80s.:
- This one has 5 connections.  Both the gas tank AND the carb fuel bowl vents go to it.  Otherwise it works about the same, don't remember why the extra connections.  One might be the PCV.

Since they went to fuel inj., no more float bowls, therefore they went back to the simple type.  My '80 J**P and the '73 WM both have the complicated one.  When I put the '91 TBI in the J**P, I went back to the simple one, which, conviently, happened to be in my parts '71 T'all!

Here's something important:  If you take out the charcoal canister, what are you going to do with the fuel tank vent?  If you plug it, you'll suddenly find it very hard to fill your gas tank.  If you leave it open, all sorts of crap can make it's way into your tank.


'67 1000B step-side p/up  BG241 + 4spd
'70 1200D 4x4 Travelette 392 4spd
'71 1010 Travelall  392 auto
'73 1210 Wagonmaster, 392 auto