fuel tank vent line

[961uz4b]

On the tank of my hilux I have a send, return and vent line, originally the vent line was running to a charcoal canister in the engine bay that I have now binned, so the vent now just has a tail of hose hanging off it and I’m a little unsure what the best way to deal with it is,
I was in a Toyota dealership the other day and actually noticed a new cab chassis hilux and the vent line simply had about a 6inch tail with a small fitting on the end, I'm guessing this was a one way valve or very small charcoal canister or something, I would like to ruin something like this.

Any suggestions?

 

[Bushwhacker]

Thats what I have clipped to the top of my tank, a one-way vent valve. My Hilux Surf was originally a diesel which have the valve already in place.

 

[gloverman]

Alot of toyotas have the little one way valves. The photos shows the system very well. I would follow that way like most non emission toyotas. Hiace van have the same valve and its easy to get at. Cheers

 

[961uz4b]

I'm still a little unsure as to what the best way to deal with the vent line is.

Do I want a one-way valve on it, if so what direction should it be plumbed in? To let air in or out?

I have been told to block the vent line and use a fuel cap with a built in valve but I would like to keep the stock cap.

Or do I want a roll over valve? Like what motor sport connections/ revolution etc sell?

Or should I just run the hose up out of the way and put a small air filter on the end?
Someone also told me that the fuel tank needs to be under pressure with an efi system?
Got me quite confused what the best way to go is.

 

[duza]

The fuel tank does not need to be under pressure.
If your vent line goes to the engine bay, you can simply not connect it to the charcoal canister, just tie it up out of the way. However, to get your conversion engineered, you will have to have a canister fitted. My Hilux had the vent line end about a foot from the tank, so I actually extended it to the canister in the engine bay. Like you, I was going to throw it after engineering, but have decided to do the right thing by the environment and leave it where it is.
As far as one way valves are concerned, you don't want dirt etc getting into the fuel tank, so a one way valve should allow fumes to escape from the tank to the air or canister.

 

[Bushwhacker]

Yeah I know it's an old thread but I've got the exact same issue with my 1UZ Hilux. I've got a 130L long range tank and not sure how to properly set the breather hose up. I haven't got a charcoal canister.

Going by the picture, the tank breather and filler breather are both connected together via one hose and that hose houses the little one way vent valve. Should I do it like that too? Or should I run a hose from the tank to firewall and have it in there?

Any help is appreciated as ute is undrivable at this stage

The vent valve hose doesn't connect to anything at the other end, it's just clipped to the tank and runs around to the other side and vents to atmophere.

 

[Big_Lux]

Ah okay, I see now. Looking at how mine is connected, I've plumbed the tank breather hose to the hard steel line that goes to engine bay which used to go to the charcoal canister. Do you think I should do it like you've pictured?

I'm trying to rule out my idle issue and thought my tank may be contributing as it may not be venting properly

 

[Bushwhacker]

If a vacuum is being created in the tank then it could affect fuel delivery.
Just vent the breather to atmosphere near the tank.

 

[cribbj]

I think those valves are actually 2 way breather/vent valves.

They provide little or no restriction at all when the tank needs to "inhale" air to keep from collapsing due to fuel usage, however there's a small restriction when the tank is under pressure, ie from the car sitting out in the hot sun. Here's one manufacturer of aftermarket valves: http://www.newton-equipment.com/tpv6.html and there's a good explanation on their website how they work, and at what pressure.

When they do vent, due to overpressure in the tank, they should be going to a charcoal canister, then into the intake of the car via the normal EVAP system (one antipollution system that actually works and doesn't slow us down)