leaking gas from top of tank

[Kernal]

Is this a model year specific problem, pre-95?? The thread started out with a tank from a 94, the cracked tank above is from a 93, the good tank is a 96, do we know what model years the other cracked tanks were from?

IIRC Toyota has recalled tanks in the past that developed spontaneous leaks, the parts gurus would know the details.

 

[cruiserdan]

Is this a model year specific problem, pre-95?? The thread started out with a tank from a 94, the cracked tank above is from a 93, the good tank is a 96, do we know what model years the other cracked tanks were from?

IIRC Toyota has recalled tanks in the past that developed spontaneous leaks, the parts gurus would know the details.

That was FJ60/62 tanks.


The 80 tank is the same part number 93-97. 91-92 was a different part number that superceeds to the 93-up part number.

 

[concretejungle]

I gotta say this is one of the strangest issues i've seen. I've looked at this truck and tank and i can't for the life of me figure out why it keeps developing holes in the tank.

 

[Tools R Us]

Is this a model year specific problem, pre-95?? The thread started out with a tank from a 94, the cracked tank above is from a 93, the good tank is a 96, do we know what model years the other cracked tanks were from?
...

The cracked tank is a '96, donor '93. The other local rig with the same issue is a '93.

 

[cruiserdan]

Don't know, on the '96 tank the strips were grayish and have that backing, the '93 were blackish and don't appear to have it. Both look original, no evidence that ether had ever been out of the rig.

The pad part numbers are the same 91-97. If some sort of running change was made Toyota did not change the part numbers. I orderd some a few years ago when I added my sub and they were black rubber, similar to a heavy inner tube.

 

[newtomelx]

I have possibly the same exact issue. When I purchased the LX I filled up and when I got home it was dripping from the front of the tank, solution was to fill up to 1/2 tank, no drips. Replaced my charcoal canister and know I can go as much as 3/4 tank with no drips. I need to drop the tank and replace with a good/ used one from Jason (CruiserYard). Curious if changing the canister will keep pressures in the tank (or vacuum) from hurting the new to me tank. Any thoughts on this??

 

[Kernal]

Tools; thanks for the correction, now more worried, was hoping the 96-97 models were immune.

Wondering, is there a method inside Toyota where someone could look for previous reports of this problem, or a method for reporting it so someone (?Toyota tech central) can look into it? I understand our trucks are getting lotsa years and miles on them, but when does Toyota stop looking at potential issues with leaking gas tanks?

 

[jfz80]

Is this a model year specific problem, pre-95?? The thread started out with a tank from a 94, the cracked tank above is from a 93, the good tank is a 96, do we know what model years the other cracked tanks were from? .

Not to make you fret but thread started with a 95 tank.

I've had another 95, a 96 Lx , and an unknown vintage tank in place and all failed the same. One more 95 left in storage but it got moisture in it and will need cleaning/lining first.

 

[newtomelx]

My LX is a '97.....

 

[BILT4ME]

The cracked tank is a '96, donor '93. The other local rig with the same issue is a '93.

@jfz80
Have either of you been able to get a clear solution to this in the last year +? I just sprung a leak on my 96 LC and I need to pre-plan the fix. I can do the brazing myself, or I can purchase a new tank, or install a "fix-it kt".

I want to plan the best case scenario for a repair that I won't have to do again. My truck is stock, however, it has a history from the PO for at LEAST two collisions with minimally movable objects. I've driven the truck for 3 years with no fuel issues until Wed. 7/8/15 and filled up at a gas station. All of a sudden it started leaking (apparently from the top.)

I have pulled the seats and access panel to the fuel pump and it is leaking somewhere below that level, as the fuel pump access is dry. It appears to be more focused on the front of the tank. My tank only had a couple seconds of pressure when I fill up, ever, nothing like the videos of these tanks that are venting for 30+ seconds and puking fuel.

I installed a new gas cap the day I bought the truck, just because I've seen issues with other vehicles and too much evaporation (aftermarket brand)

I have NOT done the FSM test on the Evap yet. Will be doing that. I will also be replacing all rubber products leading to/from the tank.

1) Determine fuel leak location with mirror/flashlight and truck on ramps (I'm too fat to slide under a stock height truck)
2) Do FSM test on evap canister system
3) Drain/drop tank
4) Repair/replace tank
5) Replace all hoses
6) Install repaired or replacement tank
7) Drive it like I stole it
8) Step #6........

Anything else anyone would recommend?
Maybe another new OEM gas cap....

 

[inkpot]

We have swapped in good used tanks on several leaky rigs. Only one of these did a repeat. After looking over a lot of rig's tank area, we have not been able to ID a physical cause for the crack to form. Best guesstimate is maybe a weak spot in that area due to the forming if a compound curve right where it cracks, and it may be aggravated by the increased vaporization potential of modern day ethanol supplemented fuels?.?.

One local guy had his tank brazed/patched, which MAY? Be a better long range solution. I would guess that it cost $100-200 if you pull your own tank. John

 

[BILT4ME]

We have swapped in good used tanks on several leaky rigs. Only one of these did a repeat. After looking over a lot of rig's tank area, we have not been able to ID a physical cause for the crack to form. Best guesstimate is maybe a weak spot in that area due to the forming if a compound curve right where it cracks, and it may be aggravated by the increased vaporization potential of modern day ethanol supplemented fuels?.?.

One local guy had his tank brazed/patched, which MAY? Be a better long range solution. I would guess that it cost $100-200 if you pull your own tank. John

Thanks John!

I'll be pulling my own tank and doing my own brazing (not farming out). I wanted to get the feasibility of doing the brazing (drilling stop holes first) versus welding or patching.

Are the insides of the tanks coated or plain? Do I need to coat after I braze?

 

[Tools R Us]

I would MIG, then braze, but I'm overkill that way.

 

[jfz80]

I Would take it to Kevin

No unfortunately i have not and I've had other projects distracting me. I still have the one tank left that needs a good cleaning or coating but have seen 5 failures on this rig so wanting to find the cause first though I still believe inkpot is on it. Weird triple plane bend and I have zero contact at that point so I'm led to believe its lots of expand and contract cycles leading to this.


There is also a check valve and vent to inspect as well. The purge vent is in top of tank just to driver side of fuel tank access port.


The braze was least successful for me but I didn't nor know how to perform. Actually JB weld patch lasted the longest. Then the welded repair.

Inside of tank is bare metal. Not coated.

Dont believe You will be able to see with mirrors and flashlight

Also removing rear driveshaft is not required (ar least with a susp lift) but makes I waaaaaay easier and is worth I feel.


Add another step six when done

 

[BILT4ME]

I would MIG, then braze, but I'm overkill that way.

I normally would, but the only wire we run in our shop is .045 and I can't turn a welder that low with that size of wire and not make more holes than it has now. I'm sure someone can, but it's not me anymore.

I can braze with the best of them, but it's been 30 years since I've done it.

I like the thought process though!

 

[BILT4ME]

I Would take it to Kevin

No unfortunately i have not and I've had other projects distracting me. I still have the one tank left that needs a good cleaning or coating but have seen 5 failures on this rig so wanting to find the cause first though I still believe inkpot is on it. Weird triple plane bend and I have zero contact at that point so I'm led to believe its lots of expand and contract cycles leading to this.


There is also a check valve and vent to inspect as well. The purge vent is in top of tank just to driver side of fuel tank access port.


The braze was least successful for me but I didn't nor know how to perform. Actually JB weld patch lasted the longest. Then the welded repair.

Inside of tank is bare metal. Not coated.

Dont believe You will be able to see with mirrors and flashlight

Also removing rear driveshaft is not required (ar least with a susp lift) but makes I waaaaaay easier and is worth I feel.


Add another step six when done

Thanks @jfz80 ! The info on the check valve and vent as well as the internal of the tank lining were the key things I needed for my decision process. I'm going to get a quote on a new tank just enough to tell me what my time is worth....... If it's "cheap" I may choose to buy a new one....

 

[jfz80]

They are ~500 smart shopper price IIRC. Give. A shout @beno or your preferred vendor here to double check

I've started thinking about a 62 or 55 tank in back where the spare used to live. But just garage dreaming stages on that one

 

[inkpot]

They are ~500 smart shopper price IIRC. Give. A shout @beno or your preferred vendor here to double check

I've started thinking about a 62 or 55 tank in back where the spare used to live. But just garage dreaming stages on that one

Good luck with either of those tanks. 60/62 tanks are shallow but wide and long. The 55 tank is pretty darn tall.

 

[inkpot]

I normally would, but the only wire we run in our shop is .045 and I can't turn a welder that low with that size of wire and not make more holes than it has now. I'm sure someone can, but it's not me anymore.

I can braze with the best of them, but it's been 30 years since I've done it.

I like the thought process though!

I think with a light and mirror you may be able to see general area to see wet fuel spot in the area where crack usually occurs. Just a good indicator of the crack but not 100% guarantee. John

 

[concretejungle]

I will not speak for JFZ80 but we have discussed this since i "think" he welded his tank, brazed one, JB welded it... I personally would weld a flat plat (hammered to form) over the weak spot since his has cracked again where repaired.