Topic: Gas tank mod worked!

[sharpxmen]

It could probably also be done fast with a high pressure stream such that the inflow of gas does not fill the fill tube completely.  In this way, air could come out the same tube as we fill. We could develop the device, patent it, and market it for 4x4 enthusiasts who don't want to mod their tanks.  Make the big bucks!

the size is limited by the pocket of air  generated by the vent tube end which is below the top of the tank - it's an air bell effect, like when you sink a glass or bottle under water upside down, the air will be trapped inside the glass or bottle. the mod is still necessary regardless of the way you fill the tank.

[neale_rs]

Yes, but you only get the air bell effect if the fill tube comes into the tank below the level of the top surface of the tank (maybe this is how it is internally, in which case you would be correct, although from the outside it seems to be pretty close to the top).  Otherwise it is just like a bottle that can be filled without a vent tube as long as air can get out the same fill neck.

[sharpxmen]

Yes, but you only get the air bell effect if the fill tube comes into the tank below the level of the top surface of the tank (maybe this is how it is internally, in which case you would be correct, although from the outside it seems to be pretty close to the top).  Otherwise it is just like a bottle that can be filled without a vent tube as long as air can get out the same fill neck.

that is the mod, to remove the vent tube (or cut it) and that's what i was saying. there's no mod to do if you don't have the vent tube or if it's already cut close to the top of the tank. I thought that's what you were saying, to not have to do the mod - or maybe i'm missing something from what you explained, i probably don't understand the concept of what you described.

EDIT: nevermind, i understand now - you were talking about air coming out the fill tube (i kept thinking of the vent tube) - i'll have to look at my tank to understand how it would work, didn't think of that.

[stan98tj]

Stan, when you do this look for some Kilby gas tank skid installation instructions online.Maybe 4wd.com or Quadratec.com.

Follow their instructions. Once the tank is dropped you cut the vent tube which is the small tube next to the filler tube.

once you remove the sending unit, just put your hand and arm in side the tank and cut the small tube. The tube should be about 6-8" long.

Then put everything back. I have a 97TJ that was built in march 0f 96. I have seen before where someone said that the tanks did change at some point and it is only a 15 gal tank. Hopefully yours isnt!

Is there any way to make sure it is a 20gallon before taking the entire tank down?

[FourbangerYJ]

Is there any way to make sure it is a 20gallon before taking the entire tank down?

Fill your tank and a gas can, drive it home, siphon in the gas can. Or you can pour it in real slow with a funnel.

[smashcoast]

Stan i'm not sure if there is away to check out the size before dropping the tank.

So maybe wait to do it until you get a new gas tank skid. You will have to drop the tank then and you'll be able to check then.

[stan98tj]

Fill your tank and a gas can, drive it home, siphon in the gas can. Or you can pour it in real slow with a funnel.

I figure this should work given the fact the gas pump cuts off from the vent line pressure. so if i top it off and im able to pour in another gallon, that should be a safe estimate it has a 20gallon tank right?

[FourbangerYJ]

I figure this should work given the fact the gas pump cuts off from the vent line pressure. so if i top it off and im able to pour in another gallon, that should be a safe estimate it has a 20gallon tank right?

After filling up at the pump you should be able to get about 4 more gallons in. My buddy with his 97TJ 2.5L did this and was able to get 4 more gallons in his. You just need to pour it slowly with a funnel, or use a siphon. It needs to be added slowly.

[warro]

 :dance:Thanks for another great tip!!!!!!!! The tube was tough to get out. It is great to have that extra fuel. Needed it this past weekend. Took awhile to get out of an area that had a closed road.

[stan98tj]

well. i tested it out. had a little under a quarter tank left. filled about 10.8gallons till pump clicked off. then i slowly (took like 10 freakin minutes!!!!) filled 5.5 more gallons into the tank before it spilled out the fill. i think this prob means i have a 20g tank. Smashcoast, how much did you cut off the vent line? if it's about 8", should i take about half or more of it off?

[smashcoast]

I cut it all off, cut it flush with the tank or as close as you can get.

 Like I said I waited to do mine when i did my skid protection, it makes sense to kill 2 birds with 1 stone.

[drunkencityworker]

I put my kilby gas tank skid in and the mod worker great. I left 3 inches of tube on and no problems when filling