Best Fuel Cap/Seal (Fuel Smell...) Options

[GregAmy]

Broke out the '74 914 today and man does she run nice. New fuel, started right up, drives smooooth...

But I'm getting a fuel smell each time a take a hard-ish left turn. I pulled over and I can't see any liquid in the scupper area but I do see some stains below the scupper tube (could be from last fillup, there's no hose on it). No obvious leaks at the fuel level sensor or fuel neck, I replaced those gaskets some time ago when I replaced the tank for rust spots on the sides.

I have what appears to be an original metal fuel cap and I replaced the rubber o-ring some years ago (814Rubber). I did notice that when I removed the cap today that the face of the o-ring was wet. So I think a little bit of fuel is escaping past the o-ring on hard-ish left hand corners, certainly when the tank is at a higher fuel level (it was still doing it at 3/4).

What's the tips here? I'm thinking I might try gently bending the cap tabs so that it clamps harder, though it's pretty stiff to get on and off right now already. Who's got the best o-ring for the cap; anything thicker available?

Maybe it's just time to replace it again? Id' guess it's about 5-7 years old. It's easy enough to try.

I'm not too worried about it since I'm not seeing a massive liquid leak but the smell is annoying. This car is too nice to have to accept that.

Thanks! - GA

[mgphoto]

Check out this post.



http://www.914world.com/bbs2/index.php?sho...=117213&hl=

[GregAmy]

Check out this post.

OK post #2 is spot-on: that looping-hose trick is pointless because it's draining liquid fuel from an area that should not have liquid fuel under normal operations, the scupper drain.

That scupper is there to catch overflow fuel during refueling and safely dump it overboard downward; up through 1973 there's a length of hose that goes from that scupper tube straight down to the ground. After 1973 the evap control system captured that liquid overflow and ran the vapors through a charcoal canister to reduce over-refueling emissions (same as modern cars do with refueling systems).

But if you're getting liquid fuel in there during normal driving then something is wrong with the fuel cap. Go look at yours, you'll see what I mean.

So it's pretty much what I was asking above: where can I get a good fuel cap and/or seal to stop liquid from going into that scupper during left turns? I'll keep checking around but maybe I'll just give a new cap seal a shot. - GA

[mgphoto]

Working for 15 years now, this was vw’s solution.

[GregAmy]

Working for 15 years now, this was vw’s solution.

I understand. But that was VW's solution (and Porsche's post 1973) for draining liquid vapors from the vent...the scupper should not have liquid under normal operations. If you're getting liquid up there other than during refueling spillage then your fuel cap is leaking. There is no other way it can get there, assuming no leaks through the gasket interface(s) at the top of the tank.

I've ordered a replacement fuel cap to see if it resolves my fuel leak issues. Will advise... - GA

EDIT: I gave that other post another look and I think where you were getting fuel smells was from the very small hose that goes to the evap system? When I saw it the first time I thought the larger scupper hose was the one you looped. I can see how looping that smaller hose would help with that issue.

My issue is I'm getting fuel into the scupper, which drains out of the larger hose, so that's why I'm replacing the cap.

[914sgofast2]

914Rubber got a run of bad fuel cap seals a few years ago. They replaced them for free if yours was leaking.