Anyone heard of making your 15gal TJ gas tank to 20 gal ??

it can be done on TJ's, but don't expect to get 20 gallons in. i went from about 11 gallons to now close to 17 gallons on mine. you will need to drop the tank. pull the pump/fuel thing out the center of the tank. from there you need to reach in the tank with some form of cutting devise, and cut the tube that is next to the fuel filler hose as short as you can get it. i used a hack saw blade and managed to cut off about 3 to 4 inchs. hardest part was droping the tank and reinstalling it. on a side note i did watch something on TV saying something about there's a built in air space in gas tanks so the fuel and vapors can expand and some thing about if you fill it up to much it could explode.... blah blah blah, i haven't exploded yet
 
So if they blow up, why do they put the same tank that holds more in different vehicle?
 
I did it to my '99 and regularly get 18+ gallons in it...

took an hour from beginning to end...

that write-up is for a YJ...and the same procedure is not used on a TJ...

total cost to me was ~$10, since I decided to buy a new seal to install when we put the pump back in...

Greg
 
rattlecanpaint said:
So if they blow up, why do they put the same tank that holds more in different vehicle?
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It had nothing to do with safety. It was all marketing (and pretty clever I might add). They marketed two different options and didn't have to change the parts supplier for the different options. All they changed was one part - the fuel sender (and it may have been a simple calibration). They charged extra for something they were putting in the vehicle anyway. They do that a lot now with everything being computerized. They put a lot of features in various vehicles and disable them if you didn't purchase the option. I think the new Overlands have rear view mirrors that auto tilt down when backing up. The feature is there but disabled on lower models.
 
jeep9mm said:
when was it that small? My 04 is 19 gallons from the factory and when im really really low i get 17-18 in there
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'99 was the last year of the 15-gallon standard, 19-gallon optional tank...

Mangler may have the story on the YJ...but here's what they did on the TJ...

made a single sized (external dimensions) fuel tank...

had a vent tube inside the tank at a certain length that allowed you to only get 15 gallons in it...

for ~$200, you could "upgrade" and you'd get the exact same tank...except the vent tube was shorter, which allowed you to be able to get 19 gallons in it...

if you cut the tube flush with the tank, you can easily get 19+ gallons in...

the pump was the same size...just the different sending units so the guage was rights...

the entire reason I did it on my '99...was the fuel guage would never go over 3/4 tank...got the part number off the side of the tank, and it was a 15-gallon tank...the build sheet said we had a 19-gallon, but the Jeep has a salvage title...

so, ended up finding it had a replacement 15-gallon tank, but still had the 19-gallon sending unit...so a full 15 gallons only looked like 3/4 tank...

once we cut the vent tube from inside the tank, the guage now shows full...

Greg
 
I did it today and it worked i can now get about 18 gal in the tank
 
overfilling the tank can also let a bunch of liquid fuel into the charcoal can, plugging it up.. YMMV.
 
BIGWOODY said:
you are correct sir...and it won't show up until many fill ups later...
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I'm kinda surprised at that since my charcoal canister's top mounted hose was located higher than the gas filller on my YJ. Must be a TJ thing or something. Either that, or some kind of reverse syphon thing happening with a vacuum. Charcoal canister is not supposed to pull a vacuum at that port unless it's not working properly. It's merely a vent for gas vapor. (as far as I know anyway)
 
ManglerYJ said:
I'm kinda surprised at that since my charcoal canister's top mounted hose was located higher than the gas filller on my YJ. Must be a TJ thing or something. Either that, or some kind of reverse syphon thing happening with a vacuum. Charcoal canister is not supposed to pull a vacuum at that port unless it's not working properly. It's merely a vent for gas vapor. (as far as I know anyway)
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True, but if the liquid gets into the vent lines, it will make its way...
 
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