But that's not nearly as exciting as explaining why you're stuffing pantyhose full of dry rice into it!
leaking gas from top of tank (1 Viewer)
- Thread starter jfz80
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But that's not nearly as exciting as explaining why you're stuffing pantyhose full of dry rice into it!
Is your frame tweaked or something? Do I understand correctly that this is the 3rd tank that has cracked in the same place on your rig? I don't think that's coincident. Unless they were all used tanks off of rigs that were previously in accidents. Maybe accident forces, somehow tweak the tank in that exact location.
My '95 has had no problem, other my screw in the tank on accident incident. I just used a combination of tank repair paste and JB weld, with no problems, but it was a just pin hole on the top of the tank.
Maybe the body mounts are worn and causing the body to flex the tank? I don't know. Sure like to find out the cause.
If I recall correctly our tanks are bolted to the body. Other toyota trucks have them bolted to the frame, so I don't know if this is making a different as far as how much the tank flexes or not.
My '95 has had no problem, other my screw in the tank on accident incident. I just used a combination of tank repair paste and JB weld, with no problems, but it was a just pin hole on the top of the tank.
Maybe the body mounts are worn and causing the body to flex the tank? I don't know. Sure like to find out the cause.
If I recall correctly our tanks are bolted to the body. Other toyota trucks have them bolted to the frame, so I don't know if this is making a different as far as how much the tank flexes or not.
This is facinating. I have NEVER sold an 80 Series fuel tank and I do not recall ever taking a call from anyone looking for one.
Based on my clientel as opposed to any other dealer in the US I am astonished that I have never seen or heard of this before if it is indeed a repeating issue.
Based on my clientel as opposed to any other dealer in the US I am astonished that I have never seen or heard of this before if it is indeed a repeating issue.
Looking at those pixs are any of the bolts that go through the floor hitting the tank ? Im wondering if your filling it , tank "blows up" some from pressure and hitting a just a little too long bolt sticking through maybe from the rear seats mounts ?
I 'd put a blob of play doh where the crack is and put the tank back up and bolts back into the floor and see if something is leaving an indent .
I 'd put a blob of play doh where the crack is and put the tank back up and bolts back into the floor and see if something is leaving an indent .
jfz80
Cruisin’
- Thread starter
- #45
thanks RT, was needing to fill up ASAP and ended up doing just as you said; a good wipe dry and fan action.
I hope its not. I will check the body mounts for tightness as this was the culprit for my steering issues on the 55. I dont know how youd determine if they were simply worn out. I agree on it not being coincidence failing in very same spot. My buddy thinks it needs a "c" channel reinforcement in the e-brake groove to span that gap w/ more support. The truck may have been in minor accident that i dont know about. Both replacement tanks were used. Yes, i wheel it, but no harder and not even as hard as several of our members here. The 80 tank is strapped to the bottom of the body. Two straps is all the support, maybe a third would help, but i still see there being another reason behind this.
Thats because you were on the Rubithon
I did mark the area around the failure w/ a smear of FIPG and placed tank back in position, removed, and found no FIPG on the body or any bolt heads. Maybe ill try something a lil thicker like the playdough mentioned. I also doubled up on the tank pads on the second and third install to try and clearance the tank a bit further away from any contact points.
I DO NOT believe the crack is from contact. I believe it to be from the tank folding/bending and pinching this intersection area of two stamped curves. However the failure is directly above the forward retaining strap.
Here was what i tried for a repair
Ill have the opportunity to check it again because the welds made on friday lasted until sunday
Anything else to check while its out?I did test the vent tube both in june and last week. I blew in the vent line at the charcoal canister, it returned airflow when i let off. I also followed the FSM for cleaning the charcoal canister.
I do not have it out yet, so i am not certain if the leak is from another crack, a faulty weld, or just the same pressures transferred to the edge of the welded reinforcements. Again it leaked just after filling up (but hole is on top)
found a local fuel cell but would have to redo to run our pump/filter; or i may be looking at the replacement tank from roger davis???
That does not sound right,
are you certain that the large vent line that comes out of the charcoal canister and terminates in the frame is clear of any obstructions?
i was very astonished also. I helped him lift the repaired tank up and in. While there, i looked at everything also to see if i could see any issues at all. None that i could tell. I looked at my rig (same model year) and all the straps and associated connections are the same. As well as the location of his tank in relation to the frame, t-case, ect.
I have no clue why this is happening. My first speculation was that the straps were too tight which would cause the tank to bow. BUt after checking the clamp distances between how far we tightened his down vs. mine, they were the same.
I have no clue why this is happening. My first speculation was that the straps were too tight which would cause the tank to bow. BUt after checking the clamp distances between how far we tightened his down vs. mine, they were the same.
jfz80
Cruisin’
- Thread starter
- #48
I should clarify here.... i blew in the vent line that goes from charcoal canister to the top of tank....this line returned flow. when i cleaned the canister per the fsm i blew through the media at a specified cfm which i had to estimate, but air did come out of the line that is bolted to inside of frame. I saw someones issues (maybe Koffer) that had a rusted up and cloged exit line.
jfz80
Cruisin’
- Thread starter
- #49
I got the tank dropped today and its cracked at the weld that i had made for a repair. Im thinking possibly this time of making a "patch" w/ a hole in center and line it up w/ the fracture, rosette weld the center of sorts and then around the edges. Any other ideas?
Unfortunately you cant reach the inside of the crack due to the baffles.
surely this wouldnt be due to the custom exhaust run over the frame just on the other side of the driveshaft. Its really not much closer than the stock muffler, and it seems the vent line would take care of any expansion. I did check the vent line where it terminates inside the front frame rail for any blockage.
Folks had mentioned checking the body mounts....How would you go about this. I mean the bottoms are double nutted, so can i loosen the bottom nut and check torque on the inner nut, or will i have to pull carpets and get to the top side of the bolts? thanks fellas.
Unfortunately you cant reach the inside of the crack due to the baffles.
surely this wouldnt be due to the custom exhaust run over the frame just on the other side of the driveshaft. Its really not much closer than the stock muffler, and it seems the vent line would take care of any expansion. I did check the vent line where it terminates inside the front frame rail for any blockage.
Folks had mentioned checking the body mounts....How would you go about this. I mean the bottoms are double nutted, so can i loosen the bottom nut and check torque on the inner nut, or will i have to pull carpets and get to the top side of the bolts? thanks fellas.
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jfz80
Cruisin’
- Thread starter
- #50
Would anyone (knowledgeable 
) recommend drilling the crack in the tank before welding a repair. Could it be the crack that is spreading, though doubtfull cause we got good penetration on the weld. I plan to add a rod along the ebrake groove to prevent any folding of the tank. I still agree this is stemming from another location, and this reinforcement may just move the stress point to somewhere else on the tank...................but im getting good at dropping and swapping now 
) recommend drilling the crack in the tank before welding a repair. Could it be the crack that is spreading, though doubtfull cause we got good penetration on the weld. I plan to add a rod along the ebrake groove to prevent any folding of the tank. I still agree this is stemming from another location, and this reinforcement may just move the stress point to somewhere else on the tank...................but im getting good at dropping and swapping now
Yes stop drilling is recommended when repairing cracks, but I do not think that is goign to help. you need to figure out what is causing this,
have you considered plumbing in a vacuum gauge to the tank and see what kind of pressures are being generated in the tank?
have you considered plumbing in a vacuum gauge to the tank and see what kind of pressures are being generated in the tank?
jfz80
Cruisin’
- Thread starter
- #52
Thanks RT.... hadnt thought of that. Could just hook up to the vent line and leave the inspection cover off so i could read while driving. Tried the soap trick just for the afternoon, seems to work but i didnt fill the tank. Excuse my ignorance here, but is that stop drilling? (or step, as in w/ a step bit)
Only other observation i made is that today, for the first time the tank straps could be secured to the point the two halves of the stap bottomed out on each other. I have never witnessed the straps this tight. It did not seem that hard to wrench em down either. When this whole saga began, and i first removed the tank there was a 1/2 to 3/4'' gap b/w the two halves of the strap. Im am wondering if by some odd stroke of luck the bolts had been backing out and allowing the tank to have a gap above it. And when i reinstalled i only tightened to the point that they were at during removal.
Again, seems highly unlikely for as many times as the tank has been refitted at this point, but it definately bolted up closer/tighter today.
Only other observation i made is that today, for the first time the tank straps could be secured to the point the two halves of the stap bottomed out on each other. I have never witnessed the straps this tight. It did not seem that hard to wrench em down either. When this whole saga began, and i first removed the tank there was a 1/2 to 3/4'' gap b/w the two halves of the strap. Im am wondering if by some odd stroke of luck the bolts had been backing out and allowing the tank to have a gap above it. And when i reinstalled i only tightened to the point that they were at during removal.
Again, seems highly unlikely for as many times as the tank has been refitted at this point, but it definately bolted up closer/tighter today.
At the tip of a crack there will be distressed metal, micro fissures along the grain of the metal, also the tip of the crack is where all stress in a part will wind up, this is what makes cracks grow, the goal is to drill a clean round hole, this remaining round ring of metal will take the load and spread is out some, there is more metal in a ring than a point, so you find the end of the crank and a little more and you drill a hole, to catch the damaged metal,
in your case you need to weld up the hole afterward, if you think you can fill a hole that big you can drill out the whole cracked area and then weld it shut,
this page has a good picture of stop drilling a crack
RaBe's Cymbal Page: Cymbal Maintenance
as for hooking up a gauge, I would pull the "from tank" line off of the charcaol canister, put in a "T" ands then add some more hose on the t and hook it back into the canister, off the third leg run a line into the cab and hook it to a vacuu,/pressure gauge
kinda like this setup I did for EGR
https://forum.ih8mud.com/80-series-tech/111750-alternate-egr-tests-p0401.html
Not sure I would leave it hooked up like this wile it was parked, if there were a leak it could fill the cab with vapors and make a nice explosive fuel/air bomb.
If there is not a problem with excessive positive/negative pressure then the next suspect is structural, tweaked frame or something,
in your case you need to weld up the hole afterward, if you think you can fill a hole that big you can drill out the whole cracked area and then weld it shut,
this page has a good picture of stop drilling a crack
RaBe's Cymbal Page: Cymbal Maintenance
as for hooking up a gauge, I would pull the "from tank" line off of the charcaol canister, put in a "T" ands then add some more hose on the t and hook it back into the canister, off the third leg run a line into the cab and hook it to a vacuu,/pressure gauge
kinda like this setup I did for EGR
https://forum.ih8mud.com/80-series-tech/111750-alternate-egr-tests-p0401.html
Not sure I would leave it hooked up like this wile it was parked, if there were a leak it could fill the cab with vapors and make a nice explosive fuel/air bomb.
If there is not a problem with excessive positive/negative pressure then the next suspect is structural, tweaked frame or something,
jfz80
Cruisin’
- Thread starter
- #54
Thanks RT... i googled the process but thats a handy link too. Ill think i could fill the hole that would cover the crack, however i think there are tiny fissures across an entire area of the tank. Ill remove the paint and inspect both tanks further.
again thanks again, a real help
except this part
[/qoute]
Not sure I would leave it hooked up like this wile it was parked, if there were a leak it could fill the cab with vapors and make a nice explosive fuel/air bomb.
If there is not a problem with excessive positive/negative pressure then the next suspect is structural, tweaked frame or something,[/quote]
again thanks again, a real help
except this part
[/qoute]
Not sure I would leave it hooked up like this wile it was parked, if there were a leak it could fill the cab with vapors and make a nice explosive fuel/air bomb.
If there is not a problem with excessive positive/negative pressure then the next suspect is structural, tweaked frame or something,[/quote]
jfz80
Cruisin’
- Thread starter
- #55
...so what size tires can i fit ???
Anyone care to entertain me by going out and checking their tank straps and reporting if they are cinched down until the buckle of the straps (angle/threaded portion) are flush? Or is their a gap remaining?
Starting to think the unlikely that the tank had worked loose b/c as mentioned the first time i went to remove teh tank the straps had every bit of 1/2 gap b/w the two mounting surfaces of the strap.
Assuming you can can loosen bottom nut, and torque inner bottom nut w/out accessing top side of body mount bolt. All body mounts are tight (well i did not check the two under the radiator).
also i wire brushed the one tank i have out at the moment and the metal has lots of comma shaped fissures in it (trying to get them to show up on photo). Im wondering if this is stress marks from the initial stamping or from flexing while in place??? i need to drop, sand, and inspect the other as im afraid if its flexing both have been victim.
Anyone care to entertain me by going out and checking their tank straps and reporting if they are cinched down until the buckle of the straps (angle/threaded portion) are flush? Or is their a gap remaining?
Starting to think the unlikely that the tank had worked loose b/c as mentioned the first time i went to remove teh tank the straps had every bit of 1/2 gap b/w the two mounting surfaces of the strap.
Assuming you can can loosen bottom nut, and torque inner bottom nut w/out accessing top side of body mount bolt. All body mounts are tight (well i did not check the two under the radiator).
also i wire brushed the one tank i have out at the moment and the metal has lots of comma shaped fissures in it (trying to get them to show up on photo). Im wondering if this is stress marks from the initial stamping or from flexing while in place??? i need to drop, sand, and inspect the other as im afraid if its flexing both have been victim.
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Ill have the opportunity to check it again because the welds made on friday lasted until sunday
...
My repair method would have been ether braze or solder. It's difficult to get a gas tight seal with weld and it's much more solid than the sheet metal, making cracks around the weld likely. Braze and solder flow better into the crack, seal better and are more flexible.
jfz80
Cruisin’
- Thread starter
- #57
I agree with you; from what ive read brazing is the prefered method. I do not have access to that however and two radiator shops replies were: that they dont do that, and they would weld it. I had a friend help me weld as hed done similar repairs in the past to tanks and the price was right. I have the original oem tank that first cracked on me and I plan to repair this one in that manner once i find the place/person w/ the equip. I have a soldering iron but didnt know if it was permanent enough.
thanks for the response.
and btw 5 for 5 locally on tank straps being tightened till they bottomed out confirming my suspicion that it worked its way loose. Still seeming unlikely seeing as how there are two straps and noone else has reported this......but on that note; check yer tank staps
thanks for the response.
and btw 5 for 5 locally on tank straps being tightened till they bottomed out confirming my suspicion that it worked its way loose. Still seeming unlikely seeing as how there are two straps and noone else has reported this......but on that note; check yer tank staps
Took a look at the fuel tank on what as far as i know is an undisturbed 96 fuel tank.
At the outboard end the two "L" brackets are seated against eachother, no gap,
I would remove the extra padding, it did not help as it cracked again and it may hurt by making the tank "too big" in a sense for the straps.
At the outboard end the two "L" brackets are seated against eachother, no gap,
I would remove the extra padding, it did not help as it cracked again and it may hurt by making the tank "too big" in a sense for the straps.
jfz80
Cruisin’
- Thread starter
- #59
cracked tank V 6.0
Ok since fuel tank pressure is back on subject i thought id update this thread.
Tank and or repaired tank #6
still no good
It has become much less frustrating to just keep filling up half tank at a time...Until you drive to tellico and it takes a half-dozen fillups to get there or read Cdans post about the fuel cooling the pump inside.
+Ive checked the body mounts by loosening outer nut, and torquing the inner nut to man tight status.... none of them budged so i think the body mounts are all tight.
+Ive welded two tanks just to see the crack appear next to the weld. One I just welded the crack, one was stop drilled first then welded.
+I braised one tank only to have it last a week (with NO wheeling) after taking a month to get it back from the local tank repair guy.
+So far JB weld has been the best solution lasting 6 mos. Makes me think of going Brians route with a hole patch putty and a healthy schmear of JB.
RIP billy mays hayes..... wonder if they still make the mighty putty
+New gas cap, vent lines are clear(and terminus at frame rail), Charcoal canister passes FSM test.
Ive followed most all the advice here yet about removing extra padding, using modeling clay on top to look for obstructions, etc to no avail. I have not yet hooked a vaccuum guage to the line as RT suggested but that will be the next course of action.
I have managed to trim it down from 5 hour event to a mere 1h 45 min swap
Ok since fuel tank pressure is back on subject i thought id update this thread.
Tank and or repaired tank #6
still no goodIt has become much less frustrating to just keep filling up half tank at a time...Until you drive to tellico and it takes a half-dozen fillups to get there or read Cdans post about the fuel cooling the pump inside.
+Ive checked the body mounts by loosening outer nut, and torquing the inner nut to man tight status.... none of them budged so i think the body mounts are all tight.
+Ive welded two tanks just to see the crack appear next to the weld. One I just welded the crack, one was stop drilled first then welded.
+I braised one tank only to have it last a week (with NO wheeling) after taking a month to get it back from the local tank repair guy.
+So far JB weld has been the best solution lasting 6 mos. Makes me think of going Brians route with a hole patch putty and a healthy schmear of JB.
RIP billy mays hayes..... wonder if they still make the mighty putty
+New gas cap, vent lines are clear(and terminus at frame rail), Charcoal canister passes FSM test.
Ive followed most all the advice here yet about removing extra padding, using modeling clay on top to look for obstructions, etc to no avail. I have not yet hooked a vaccuum guage to the line as RT suggested but that will be the next course of action.
I have managed to trim it down from 5 hour event to a mere 1h 45 min swap
Why don't you just buy a new tank and stop messing around with used and old ones?
