Fuel Tank Vent???

[Hurra912]

Can anyone tell me the exact function of #47 in the attached picture? I am assuming it is a charcoal filter of some kind, but not certain. Does the line that exits the box just vent out into the trunk, or is there something on the end? The end of my hose has long since rotted away so I don't know if anything is missing. If the box(#47) is a filter, where can I get a replacement?

Thanks,
Wayne

[WFBowen]

Wayne:
That's the expansion tank which sits up by the windshield. As I remeber, unless you have a 912E, you don't have a charcoal filter box - I think those came after the 70 model. I'll double check my 68 this weekend, but look for a hose adapter up by the gas filler neck - near the cap. This should be where the hose continues to vent from the expansion tank, but I'll check mine to be sure.
Bill.

[WFBowen]

Here's what my 68 has:
Of the variations shown in the diagram, mine has the simple "loop" (61, 62, 63, etc.) with #61 coming out of the tank, making the high loop and then returning to vent out of the car near the middle-rear of the gas tank mounting flange. No expansion chamber, etc.