Fuel Pressure in Tank

[Boaf 32]

All,

Very early in my build, I had to replace my fuel tank as it could not be welded. The new tank from SOR did not have a vapor recovery system. I called them and they said it was not needed in the replacement tank.

I took it out for a short ride around the block and parked it (tank only had a few gallons). Opened the gas tank cover to add fuel and the pressure was explosive, definitely not normal.

I read a few Threads(1) Thread 2 and looking for a solution to vent the pressure. I kept the old vapor system but may not have room for it in the original location.

Has anyone had to add venting to their LC and what is the safest way to do it?

Thanks.

Boaf

 

[JohnnyC]

Get a vented gas cap

 

[sggoat]

I have the same problem. Originally, with the OEM tank, never had press in the tank. Had to install a new tank (from CCOT) due to the bottom rusted out on the old. Over the several yrs since new tank was installed, tank pressure seems to have gotten much worse. (same gas cap as the OEM)All the evap vent piping was run up to the charcoal canister through the original plastic check valve. Could it be the check is finally locked up, and not allowing vapors to be vented into the canister?(the canistor is not connected to the intake, merely vented to the atmosphere on the bottom connection)
Don't know if this is Boaf's prob or not, but it sounds similar---

 

[Solace in Solitude]

^^X2 The easiest way is a vented gas cap... buy one or drill a small hole in an unvented gas cap.

 

[Boaf 32]

Get a vented gas cap

Yep, this is the gas cap I have from Cruiser Corp.

 

[Solace in Solitude]

So, your tank is building pressure even though the gas cap is vented?

I don't know how that can be... the pressure should constantly escape thru the vented cap... unless your fuel tank is building an unwieldy (dangerous) amount of pressure...

Are you sure the vented cap is actually venting? Or, that Cruiser Corps sent you the correct cap?

 

[Boaf 32]

So, your tank is building pressure even though the gas cap is vented?

I don't know how that can be... the pressure should constantly escape thru the vented cap... unless your fuel tank is building an unwieldy (dangerous) amount of pressure...

Are you sure the vented cap is actually venting? Or, that Cruiser Corps sent you the correct cap?

Here is the cap they sent. I don't think it is vented....I'll double check..yep built up an excessive pressure. Think that is playing havoc with my fuel pressure as well. Thanks

 

[Solace in Solitude]

I don't see where that cap is advertised as vented...

I'd take it to a local parts store and ask for a matching vented cap... probably be cheaper than drilling a small hole in the one you have.

 

[Spike Strip]

Those caps are vented, but only for VACUUM. You need a cap that's vented for both Pressure AND Vacuum.

There are different caps that fit depending on whether or not you have a fuel filler door or not.

I used this one on my 60 and 40, but had to bend the tang over so it would fit in the 40.

Amazon.com: Motorad MGC-806 Fuel Cap: Automotive

 

[Solace in Solitude]

Those caps are vented, but only for VACUUM. You need a cap that's vented for both Pressure AND Vacuum.

There are different caps that fit depending on whether or not you have a fuel filler door or not.

I used this one on my 60 and 40, but had to bend the tang over so it would fit in the 40.

Amazon.com: Motorad MGC-806 Fuel Cap: Automotive

Thanks Spike... I never thought of that!

 

[Boaf 32]

Thanks all, my understanding a vented cap was vacuum and pressure. Sometimes getting a factory appearance is not that important.

Boaf

 

[Spike Strip]

Vented caps are not vented for pressure for smog reasons, fumes are supposed to go through the charcoal canister, not out the fuel filler.

I'm sure (mostly) there is an early pre-smog or non-USA? Toyota cap that would be both pressure and vacuum vented.

Perhaps @beno knows?

 

[Solace in Solitude]

Or, he can drill a small hole...

 

[Boaf 32]

The hole wins. No more huge pressure releases. Thanks.

Boaf

 

[Spike Strip]

You're gonna smell gas. Also, supposed to be dangerous if there's a roll-over (that's why they're valved). Your call.

 

[Boaf 32]

Temporary solution until I get a Vented / Pressured gas cap. I appreciate it, thanks.

Boaf

 

[Solace in Solitude]

The proper way is to, as @Spike Strip mentioned, add the evaporator (separator), charcoal canister, VCV and BSBP back and plumb it properly.... that's how I would do it, but the hole in the cap lets you drive it until you can get the required parts together... if you elect to do it...

By venting directly, you are personally responsible for the hole in the ozone

... and there is the chance of gas leaking, if you turn it upside down, and a potential fire/explosion.

Some people vent their tank to atmosphere by drilling a hole in the cap... in fact, @Downey suggested I drill my aux tank cap when I installed the aux tank. But, my main tank already had all the requisite evap and charcoal and breather, so I plumbed the aux tank just like the main tank and shared the eval and charcoal canister.

I think you can buy an aftermarket charcoal canister... or you can contact Georg (@orangefj45 ) and he can most likely hook you up with the parts you need.

HTH

 

[WildernessRimFab]

I had the same problem with my 72 fj40. I installed a stant #10583 locking vented cap that looks like this and it works great.
http://www.summitracing.com/parts/snn-10583/overview/make/toyota/model/land-cruiser
I got it locally at a NAPA.

 

[SteveH]

Nice temporary fix, but I would vent the tank with a hose that ran high somewhere. When you fill your tank and go around a corner, you will have gasoline running down the side of your truck, which won't be nice to your paint. In the meantime, don't fill your gas tank over 3/4 full.

 

[Boaf 32]

Thanks All,

I plan on getting a vent / pressure gas cap until I can get the charcaol Canister. I had the original vent evaporator (3 plastic pipes), never had a charcoal canister so that will be an experience installing it.

It's a tempo fix for now. The truck is not on the road, just prepping (but close). I will research the canister. @orangefj45, can you provide some links to those parts and how it is hooked up? Thanks

Cheers,

Boaf