Fuel tank venting system

[uladk84]

Hello all,

I have a 72 crossover that I'm restoring, and I'm in the process of untangling the PO's changes. I found couple issues with the fuel vent system.

The first is that the PO blocked off all venting from the tank. The two lines from each side of the tank eventually join together to form one big, closed loop. An electronic fuel pump has been installed to probably overcome the vacuum that formed in the tank as it emptied. Should each vent line join to a T connector and then to the air intake? Or should it go to a carbon canister? There was no canister in the van, but there is a pedestal platform near the "paint lid" access cover to the filler neck. What was originally mounted on that?

The second issue is that one of the vent tubes that goes up to and down from the air intake vent has snapped off after the expansion unit. I can't reach to repair that without removing the rear corner body panel. Would there be any issue skipping that section and just running the tube from behind the spare wheel well straight to it's final destination (air intake/canister)?

Cheers,
Lewis

 

[ozziedog]

Hey there. I had a 72 once that I used for parts as it had major metal cornflake issues. Up inside the air vents on each side was a bulb for want of a better word, looked a bit like those gas canisters that the kids leave lying around but maybe two or three times as long. The fuel system vents up to this bulb / condensing unit then I believe it returned to the tank on both sides. This was all constructed with sections of pipe with flexible fuel pipe as connectors. If one is missing, I’m guessing it’s required as VW were continually trying to improve the vent system because of issues it caused. If you shoved a new second hand one up there, it shouldn’t be too much of an issue to get it up there then bolt it with a handlebar clamp around it but bolt it through the inner skin. There are two sections on that inner skin and if you wanted to, you could take off the inner one with just drilling out a few rivets, bolt it on and then rivet the inner section back on so that you don’t see the bolt head. I might paint it all black so you didn’t see the bolt and clamp too. The flexi fuel pipe to use now days is another can of worms, but the consensus of opinion is to use a pipe supplier rather than a motor factor type place. I might have a picture of this bulb / condenser thingy somewhere and I’ll try and find it for you.

Ozziedog,,,,,,,, But I’m now off Dubs In The Castle at Caldicot :mrgreen:

 

[ozziedog]

Here you go













Ozziedog,,,,,,,, have fun :mrgreen: :mrgreen: :mrgreen: