Fuel tank filler tube mod to convert 15 gallon tank to 19 gallon

[Gollywomper]

All right thanks guys. I am dropping the tank now. I was just wondering if I needed to chop it or not, but if it is truly a 19 it is probably already short. Thanks for the advice as always.

Look between the fill and vent hose on the tank. There will be a 15 or 19 stamped there.

 

[jjvw]

Hey, so as others have mentioned, you really can't trust the gauge that well. In order to know that you've really run out of fuel, you have to actually run out of fuel.

But you should also keep in mind that even if you really run it out, you might still be able to put in only 15 gallons before it starts clicking you out. That doesn't necessarily mean that the tank is full (it's not overflowing); it just means that your vent tube is telling the pump to click you out, because it thinks the tank is full. If that happens to you, you can read on this thread and others how to fix that problem.

The gauge is perfectly accurate and reliable once you learn how to read it. The problem is that people assume it means something it doesn't.

I know when I ran the tank dry, the needle was below the E and I put in just over 20 gallons.

 

[eastbloc]

The gauge is perfectly accurate and reliable once you learn how to read it. The problem is that people assume it means something it doesn't.

IQ lvl 1000!
Ever thought about being a lawyer, politician or simply work for car marketing?
I don't think there is anything one can not get away with using that logic!

 

[jjvw]

IQ lvl 1000!
Ever thought about being a lawyer, politician or simply work for car marketing?
I don't think there is anything one can not get away with using that logic!

Recently I bought some turkish bath towels. They are thinner and larger than what we are used to. But the claim is that they are softer, absorb just as well, but dry more quickly than your typical fluffy towel. But they must be laundered correctly in order to work properly!

Several of the descriptions for these Turkish bath towels clearly state if you don't like them, you are using them wrong.

So far, I think they are a pretty great towel!

 

[eastbloc]

Recently I bought some turkish bath towels. They are thinner and larger than what we are used to. But the claim is that they are softer, absorb just as well, but dry more quickly than your typical fluffy towel. But they must be laundered correctly in order to work properly!

Several of the descriptions for these Turkish bath towels clearly state if you don't like them, you are using them wrong.

So far, I think they are a pretty great towel!

Pretty much, consistent inconsistency.
You are on point no argument, i simply like how you worded it

 

[SSTJ]

The gauge is perfectly accurate and reliable once you learn how to read it. The problem is that people assume it means something it doesn't.

Sure, agreed. But of course with 20+ year old Jeeps, there's also the chance of a faulty gauge, right? Either way, I just think the OP can't rely on the gauge to tell him when he has 0 gallons in the tank.

I know when I ran the tank dry, the needle was below the E and I put in just over 20 gallons.

Ha, wow. The last time I ran the tank dry I still hadn't gained access to (or knowledge of) the full 19 gallons, so I've never had the chance to try to put in more than 19.

 

[jjvw]

... Either way, I just think the OP can't rely on the gauge to tell him when he has 0 gallons in the tank.



...

He certainly can once he learns what his gauge is telling him, not what he thinks it is telling him. Right now, he's doing it wrong. Not that there is any harm in doing so here.

 

[ac_]

He certainly can once he learns what his gauge is telling him, not what he thinks it is telling him. Right now, he's doing it wrong. Not that there is any harm in doing so here.

Sounds like I need to open my mind to the Matrix.

 

[ac_]

Look between the fill and vent hose on the tank. There will be a 15 or 19 stamped there.

View attachment 307991

Nice Trick!

 

[Gollywomper]

The gauge is perfectly accurate and reliable once you learn how to read it. The problem is that people assume it means something it doesn't.

I know when I ran the tank dry, the needle was below the E and I put in just over 20 gallons.

This didn’t make sense when I read it earlier. I just got my tank reinstalled and of course the light came on as there was only a few gallons in there. Then I took a second and looked at the gauge. Lol
The light comes on at 1/8 of a tank. Not on empty. 1/8 of a 19 gallon tank is real close to 3 gallons as suspected. Add another gallon for safety and we are at 4 gallons when the light comes on. Lmao. It’s the simple things in life.

 

[mrblaine]

This didn’t make sense when I read it earlier. I just got my tank reinstalled and of course the light came on as there was only a few gallons in there. Then I took a second and looked at the gauge. Lol
The light comes on at 1/8 of a tank. Not on empty. 1/8 of a 19 gallon tank is real close to 3 gallons as suspected. Add another gallon for safety and we are at 4 gallons when the light comes on. Lmao. It’s the simple things in life.

All of that and there is generally a built-in small safety factor. On my Dodge tow rig, it says that there is a small reserve of 5 gallons when the overhead reads 0 miles to empty and the gauge is below E. Wonder what the TJ manual says about it?

 

[Gollywomper]

My new F150 with a 36 gallon tank. Even with less than 20 miles left on display it has never taken more than 31 gallons. Lol.

What I disliked about my TJ 15 gallon tank is it was only 11 gallons and the light came on. Hopefully my vent tube mod will get me a few more gallons of fuel capacity.

 

[mrblaine]

My new F150 with a 36 gallon tank. Even with less than 20 miles left on display it has never taken more than 31 gallons. Lol.

What I disliked about my TJ 15 gallon tank is it was only 11 gallons and the light came on. Hopefully my vent tube mod will get me a few more gallons of fuel capacity.

You have to consider the logic from the other direction. If the light came on about the same time the needle hit E and you had 1-2 gallons left before the engine sputtered to a stop, the uproar from the public would be outrageous. Now we just get eternal sniveling and bitching over the stupidity of Jeep engineers and their faulty gas gauges that don't tell the truth. I know which one I'd pick on the engineering side.

 

[Gollywomper]

You have to consider the logic from the other direction. If the light came on about the same time the needle hit E and you had 1-2 gallons left before the engine sputtered to a stop, the uproar from the public would be outrageous. Now we just get eternal sniveling and bitching over the stupidity of Jeep engineers and their faulty gas gauges that don't tell the truth. I know which one I'd pick on the engineering side.

The common misconception is the light coming on and we think it’s on E. It’s not, it’s on 1/8th. It is just reminding you to look for a station before too long. Me changing my sending unit had to do with the erratic behavior my gauge had. My sending unit was pretty much worn out.

 

[SSTJ]

He certainly can once he learns what his gauge is telling him, not what he thinks it is telling him. Right now, he's doing it wrong. Not that there is any harm in doing so here.

Ok, you've got me interested: how does one read the gauge properly? According to my manual, the light-on means 3 gallons left (at least, in my 97 SE). And then I know from experience that it hits E when I still have about 1.5–2 gallons left. Let me know what you have in mind?

 

[jjvw]

Ok, you've got me interested: how does one read the gauge properly? According to my manual, the light-on means 3 gallons left (at least, in my 97 SE). And then I know from experience that it hits E when I still have about 1.5–2 gallons left. Let me know what you have in mind?

I know by looking at my gas gauge about how many miles I normally should have traveled. 110-120 miles at half on the gauge. I know about how much gas I expect to put in when the light comes on somewhere around 210 miles. About 14-15 gallons. I know I have about 5 gallons left with a conservatively estimated 60-70 miles of range left. I know I run out of gas right below the E because I have fully emptied the tank once and come close many times.

I have learned what my gas gauge is telling me because I have paid some attention to it over the years. I don't know why this is complicated.

 

[Old_Crow]

According to the build sheet, my rig came with the 19-gallon tank. I've run it down past the red to the E line a couple of times and never pumped more than about 16 gallons in it.
Recently, due to my stupidity of using a gas can with water in it, I had the tank dropped and drained. The shop put a fresh 5 gallon can in it when they got it back together, then drove it around the block. When I picked it up, I took it straight to the gas station and added an additional 15 gallons. At least now I know it'll really hold 19 gallons.

 

[Gollywomper]

Ok, you've got me interested: how does one read the gauge properly? According to my manual, the light-on means 3 gallons left (at least, in my 97 SE). And then I know from experience that it hits E when I still have about 1.5–2 gallons left. Let me know what you have in mind?

Which is exactly what it should read.

 

[BlueDemon98]

It turns out that I did not keep the fuel tank that I modified, after seeing some damage to the tank in two places. But this is a plus for this thread, since it allows a clear comparison between the two fuel tanks that Jeep offered on 1997-1999 Wranglers. Yesterday I went to FN Jeep in Colorado Springs and bought a stock 19-gallon fuel tank from a 1998 4.0L. It is part no. 52018768AB, what Jeep lists as the 19-gallon tank. You can see the part number in this photo:

View attachment 95860

The vent tube on the inside extends only a short way into the tank, as this photo shows.

View attachment 95863

You can also see that the fuel filler tube is considerably shorter than the one on the 15-gallon tank. Here is another picture from the 19-gallon tank, showing this part better.

View attachment 95865

FN Jeep also had a 15-gallon tank from a 1998 Wrangler, like the one that came with my 1998 SE, pictured in my previous post. According to The 1999 Jeep Wrangler Owner's Manual (I found a physical copy), the 15-gallon tank still came standard on 4-cylinder models in 1999, like it did on the 1997-1998 4-cylinder models. Here is a picture of the inside of the 1998 Wrangler 15-gallon tank that FN Jeep has.

View attachment 95866

To be clear, both tanks are identical in size. Both have a 19-gallon actual capacity. The so-called 15-gallon tank only has a longer fuel filler tube and a longer vent tube, preventing more than a 15-gallon capacity.

As part of the 15 to 19 mod, does it matter if the longer fuel filler tube in the 15-gallon remains the same length? I'm assuming only the vent tube needs to be trimmed down. Thanks for the great comparison.

 

[BlueDemon98]

My 97 SE 2.5L has the 15 gal tank. I removed the tank and cut the vent pipe, like magic it's a 19 gal tank now.

Did you replace the pump, and if so, did you install a 19-gallon fuel pump? If that is the case, how is the gauge behaving after the mod? Thanks