Fuel tank vent puking gas !!

[GregWeld]

The other issue is the vent line may be too small -- once some gas gets up inside the vent tube -- the pressure builds up behind it and pushes it out. A LARGER vent tube will allow the pressure to pass the fluid and not push it up and out. Think of a straw....

Hard line has a larger inside diameter... so hard line the same OD would be a better solution than rubber hose... BUT here's my other thought:

DO NOT loop it -- that effectively makes a "P" trap out of the vent line and any "fluid" would sit in the bottom of the "loop" and any pressure behind it would push that fluid up and out of the vent. The fluid in the loop would also block any incoming "make up" air.

[ccracin]

Originally Posted by GregWeld

DO NOT loop it -- that effectively makes a "P" trap out of the vent line and any "fluid" would sit in the bottom of the "loop" and any pressure behind it would push that fluid up and out of the vent. The fluid in the loop would also block any incoming "make up" air.

BINGO, You are exactly correct. This will not be done on ours. I added a -6 vent fitting to our tank as well as the vented cap. Hopefully it is enough.

[GregWeld]

Originally Posted by ccracin

BINGO, You are exactly correct. This will not be done on ours. I added a -6 vent fitting to our tank as well as the vented cap. Hopefully it is enough.

Of course I am!!


This ain't my first goat rodeo!

[ccracin]

Originally Posted by GregWeld

This ain't my first goat rodeo!

You ever been Bucked Off?

[GregWeld]

Originally Posted by ccracin

You ever been Bucked Off?

Sometimes it feels like the goat is riding me!

[Siv]

Still running great! I would have bent up my own lines, but I have very little time and very little money. Everything in the pictures I posted I already owned from previous projects.

Thanks again Blown353

[GregWeld]

SIV -- ^^^^^^^^^^^^^^^^^



I appreciate your work - but I would NEVER EVER EVER vent GAS FUMES into an enclosed space -- and especially where you have light bulbs/turn signals/brake lights/wiring....

You get a leak in your vent system -- hit the brakes -- and see ya sweetheart!

Of course - I'm also an internationally licensed pyro - so I think SAFETY first - which is why I'm still alive to type this.

[Siv]

The line out the top runs to a filter under the car just above the tank.

[GregWeld]

Originally Posted by Siv

The line out the top runs to a filter under the car just above the tank.

Right -- but I was pointing out IF you have a LEAK.... you have several points of failure. The actual vent is not the issue... it's the fact that you've chosen to run GAS FUMES (it's associated plumbing and fittings etc) into an enclosed space.

It could be leaking and you'd never know it until it's too late.

The 'idea' was good -- it just should be all open to atmosphere.

BTW -- I'm not dumping on you... I'm just pointing out the issues so some other readers might avoid the possible problems.

[parsonsj]

Greg's right: putting the vent in the trunk is a concern. If one can find a way to properly vent the tank and keep the plumbing on the outside of the car, that's always preferable.

However, on some cars, there's just no way to do that unless you live with leaking gas caps or a vent directly open to the atmosphere, and that has safety (not to mention environmental) issues too.

I would also observe that typical pressures within the vent plumbing rarely goes above 2 psi, and is usually at zero psi. Using quality plumbing rated at 100+ psi, plus doing consistent leak checks can mitigate that risk.

Doing it this way isn't as good as keeping it all outside the vehicle, but it's better than dumping gas on the ground during typical driving.