Gas Smell on Left Turns

I know there are a lot of older posts on this topic, and I do believe that I understand the cause of the gas smell (gas flows out of the gas tank breather tube which dumps in the wheel well).

I've installed a non-venting gas cap, a one way valve in the dump line and extended the hose quite a ways. But I still get the gas smell when I've got a full tank of gas and I make a left hand turn.

Anyone ever figure out how to definitively fix this?

It's not a huge deal, but it's fun to get everything working as well as you can!

Cole

Make sure your gas cap is sealing properly. My original one had a seal that eventually dried out and leaked enough to make the fumes noticeable. Adding an additional seal made from gasket paper worked as a temporary fix until I bought a new cap.

there is always the lighter leak tester :)

How's the seal at the sender unit?

Ernie in Wilton swears by one way valve and running the return line not only into the wheel well but down the side of car to the rear wheel well. swears it works.

Go to a BIG parking lot when there aren't a lot of cars in the way and make some sweeping left turns (pretend you're on a skid pad making a left-turning circle - that aughta do it).

Get out and take a look at your gas filler neck.

Feel around the neck a bit to see if your fingers get wet.

I'm betting on either a leaking gas cap (not all that uncommon) or some leak(s) where the neck was welded back together after shortening (also not uncommon).

You could also try pinching off the vent tube while circling and then see if it goes away.

BTW: A "vented" gas cap shouldn't let liquid gas (or fumes) escape - it should only allow air in.

Au contraire Bobby!
I solved my smell problems by shit-canning the the one way valve, extending the breather tube to the rear and making sure that the cap does not "vent" fumes in front of the cabin.
cheers!

I did Ernie's fix too. Extend that vent tube all the way to the rear wheelwell.

ernie, what do i know, im just a swab jockey

I looped mine over the hood hinge and down and out forward of rear wheel.

Okay, thanks! I'll give these ideas a try.

My extended tube goes down the side to about the passenger. I'm guessing that I need to go downwind of the passenger.

I did the trick with the one way valve and a 6" loop in the tube near the vent on the tank. It stopped the gas from pouring out on left hand turns but the vented cap on mine seems to work in both directions. If I have a 1/2 tank of gas I can push on the tank and I can hear air going in and out through the cap in BOTH directions. Kind of like CPR. If the vented cap is only supposed to work in one direction I guess that would indicate that my cap has failed. (?) If a cap is un-vented wouldn't that cause a problem on a hot day with a cool tank of gas expanding and causing pressure to build in the tank?

It does say on the cap to remove slowly because of pressure. Maybe I'll make a gasket to seal the cap and see if that helps. I'm pretty sure the gas smell is coming from the cap.

the vent line should cure heat expansion.

Hey Al....
I changed caps many times until I found one that allowed me to "un-vent" it. I caulked it with fuel proof sealant. BTW,, the "loop liquid trap" in the breather hose is a must!

Cheers from "No gas fumes Ernie"

A full unvented tank could bulge when the fuel expands. A unvented tank could collapse from the vacuum produced by the fuel pump. But usually, an unvented tank will cause the car to stall from fuel starvation.

My gas cap had a thick paper gasket and a rubber gasket. I replaced the paper one with a cork one and the cap is now very tight. I'll have to take the bride for a ride on Friday to see if it helped. Thanks for the ideas.

Cole, you could solve your problem by only turning right. Be careful, though, because continually turning to the right could eventually lead you to start leaning towards the right and that might have political consequences.
Seriously, I had a similar problem, and solved it by extending the overflow/drain line to the rear of the car.

From the breather, run a ball-check valve (allows air vent, no liquid) and put the line into a charcoal canister available at any u-pull for about $5.

Problem solved, not just moved away from your nose.

angela

Bravo Angela.....