So my gas tank finally leaked

[Bhudzallmighty]

So I filled up gas the other and I parked backwards on the driveway (front down, rear up) and gas started pouring out by the front side of the tank. I’ve had the hissing sound symptom from
My gas tank but they were not terrible. I already ordered a vc120 charcoal cannister.

I will be changing the gas tank sometime this year. What other parts should I buy when I tackle the job? I want to slowly accumulate the parts needed

Also, what are your guys’ thoughts on aftermarket gas tanks. Liland and dorman have them for about $630-$700. OEM is about $900 to -$1000.

I’m not sure my tank is repairable unless I take it down

 

[Kernal]

Could be leaking from a couple possible locations but one known issue is a small crack that shows up in the same place;
a few people have repaired that crack with good results. Unless you need a larger tank, IMHO, stick with OEM for the tank.
You could save some money by ordering from a few sources outside the US, or wait until a US dealer has a 50% off sale.

Here's a link if you haven't seen it yet:

Cracked fuel tank #2

forum.ih8mud.com

 

[BILT4ME]

I replaced:
gasket on the fuel pump
copper washers on the high pressure hose
High pressure hose
low pressure hose
Make sure to order the fill sections of hose. Do not expect to find them at an O'Reilly's or FLAPS.
Also order the vent hoses
If you look at the diagram of the fuel tank, order new gaskets / seals for every orifice.
Buy and install a new fuel sock for the fuel pump
If it has high miles, maybe a new fuel pump. I have 372K miles on my original pump.

Some like to drop the driveshaft to drop the tank. I did not, but I have a 2-1/2" lift.
Make sure to drain the tank before you start. There is a plug in the bottom for this.
PB Blaster on all the bracket hinges and straps and bolts for a week prior to disassembly.
Prepare for after and recoat whatever tank you're going to install.
New rubber straps to protect the tank to body interface or get new gaskets that are similar.

You're only going to be under there once. Do it all, do it right.

 

[Mat Jadamec]

I did the hard lines (out, return, vent OEM) to the engine and hard brake lines that run next to the tank (had to hand fab those), all the associated clamps etc, LSPV mount and valve (OEM), and the filler pipe (used parts but more work than just tank) and filler and vent hoses while mine was out. I pumped the old tank out using a siphon on the return line rather than draining.

 

[LongDuck]

Went through 1× tank repair which didn't hold, and the oil-can-denting which occurs in the section of the top of the tank right next to where the E-brake cable runs is prone to flexing when the tank pressurized during use and depressurizes when it cools. This expansion and contraction is what causes the oil can crack. It's fatigue of the metal over time.

Getting to the root cause is to fix the pressure changes within the tank, which means the Charcoal Canister and the vent solenoid valve which controls airflow in and out of the fuel tank. This solenoid valve is located under the upper intake manifold, visible between the runners and isn't expensive but is easily overlooked.

Once I changed that solenoid valve, my pressure in the tank went way down because the tank could vent properly into the Charcoal canister, as evidenced by the ability to shut off the truck, go directly to the Fuel tank cap and remove it with only a slight "whish" sound instead of a "WHOOSH" (*occasionally accompanied by liquid fuel spraying out...).

I looked for my FSM diagram, but couldn't find it... But here's my Mud thread on it from many years ago: 80 LandCruiser with Fuel Tank Leak... Options? - https://forum.ih8mud.com/threads/80-landcruiser-with-fuel-tank-leak-options.855774/

 

[Bhudzallmighty]

Went through 1× tank repair which didn't hold, and the oil-can-denting which occurs in the section of the top of the tank right next to where the E-brake cable runs is prone to flexing when the tank pressurized during use and depressurizes when it cools. This expansion and contraction is what causes the oil can crack. It's fatigue of the metal over time.

Getting to the root cause is to fix the pressure changes within the tank, which means the Charcoal Canister and the vent solenoid valve which controls airflow in and out of the fuel tank. This solenoid valve is located under the upper intake manifold, visible between the runners and isn't expensive but is easily overlooked.

Once I changed that solenoid valve, my pressure in the tank went way down because the tank could vent properly into the Charcoal canister, as evidenced by the ability to shut off the truck, go directly to the Fuel tank cap and remove it with only a slight "whish" sound instead of a "WHOOSH" (*occasionally accompanied by liquid fuel spraying out...).

I looked for my FSM diagram, but couldn't find it... But here's my Mud thread on it from many years ago: 80 LandCruiser with Fuel Tank Leak... Options? - https://forum.ih8mud.com/threads/80-landcruiser-with-fuel-tank-leak-options.855774/

Do you have the part no for the solenoid?

 

[BILT4ME]

Also something frequently overlooked is replacing the fuel tank cap with a new OEM one. Over time the seals can fail or it can get vent holes clogged. For $20, it's easy.

 

[LongDuck]

It's these 2; 17650E, and note there are 2 of them.

A new gas cap is just good PM, but realize that if your gap weren't present at all, the tank would never build up pressure in the first place, leading to the oil can crack...

A quick sidenote: perform the FSM test on yours before replacing them to be sure that one or both is failing. This gives affirmation that you're actually fixing a problem and puts the safety back on for the parts cannon. Verify the above by tracing the small vacuum tubes from the top of the Charcoal Canister to these vent solenoid to be sure I've got them right... It's been about 8-9 years since I reviewed this!