72 Dodge Brave Fuel Tank Vent

[Frank M]

Does anyone know how the side fuel tank is vented? I eliminated the rear tank on my D20 Brave and need to vent the side tank. I have a vented cap on it but can hear the tank expand or contract while it is parked. I was thinking of running a vent line from the top of the tank but do not know to where. Thanks

[RockwoodMike]

On my 73 D22, it has the main tank and in front of it is a secondary..36 gallon, 26 gallon for sizes..

On top of each tank is a vet cap mounted like the fuel sending unit..circular 5 bolts..A hose is attached to the vent and goes to a charcoal canister, to hold the fumes from the tank..

When the engine starts, the vacuum from the engine sucks the fumes from the canister and burns them off..

I don't know if your rig has a charcoal canister or not..If it doesn't then I would think the only way to vent the tank is with the vented cap..Those vented caps are made to let air in but seal the tank from not letting air out..

I have a 71 ford pickup that has a cap that can let air in or out..because it has no other way (charcoal canister) for the tank to vent..

The picture is from the full service manual available here on the literature part of the website..I use that thing all the time    

[Frank M]

Thanks for the info Mike. My MH does not have a charcoal canister.

[RockwoodMike]

My Ford pickup has the tank behind the seat..It has an inlet of 2 inches or so to fill it and 1 outlet to draw the fuel by the fuel pump..Nothing else..

So the only solution for me to vent the tank is drill a 1/16 hole in the cap as shown..On a hot day, if that vent wasn't there, pressure would build and would force fuel out the fuel line..There is no pressure with that little drill hole..

The second picture shows my 2 tanks..Vents for the charcoal canister is shown in red..

Unless you want to drop your tank out and install a vent system like mine..That would take a bit of effort..

Or drill a small hole fix it that way..

[Frank M]

Mike do you het gas smell/fumes out of the 1/16 hole?

[RockwoodMike]

Mike do you het gas smell/fumes out of the 1/16 hole?

None that I have ever noticed..If you can drill a smaller hole then that would work too..

That little hole is not going to evaporate the fuel off..It is just too small..But it is enough to equalize the tank..And that is all you are looking for..As the fuel is drawn out, that small hole will allow air in..

I have seen cars stall out because the cap won't let air in to replace the fuel drawn out..Open the cap and the vacuum is relieved..and the engine starts again..

[Bonebag]

Your 72 is vented through the fuel cap.