Fuel line problem, need part numbers.

[Skylynx]

So recently i finally managed to turn on my comanche after a few years of it sitting on my garage and i’m pretty happy about that! Though i was quickly informed by my nose that having it running was likely not the best idea due to the strong smell of gasoline coming from the puddle of it forming under the engine

I tracked the leak up after turning the truck off and fetching the garden hose just ion case and found that it was coming from this joint thingy on the fuel line, it sits almost under the break booster and it’s where the hard line turns into a rubber hose 

 

It was dry when i took the picture but it was dripping enough gas to make the truck shut off due to the low pressure after a few seconds, it was spraying all over the place.

recently i switched my transmission coolant lines to -6AN lines and i was wondering if there was a writeup here to do that same thing but with the fuel lines for these trucks? I can’t find the part number for this rubber hose section of the fuel line to replace it, and honestly the rest of the fuel system is in such bad shape that i’d like to give it new life with better components if possible, here’s some more pictures of the state it’s in.

hopefully you comanche gurus can help me find a good solution for this, thanks for the time and help!!

[ghetdjc320]

It looks like the fuel filter rubber lines are not fuel injection lines as they look like they’ve bulged under pressure. Grab some 3/8 fuel injection hose and fuel injection clamps for those. The fuel rail rubber line could be replaced by AN fittings but you’ll need a 3/8 fuel rail fitting to -6 connector. The connection that is leaking is going to need to be severely cleaned. You can then use an ac/fuel line quick disconnect tool and hopefully get that rubber kine off the hardline. There won’t be much of a gain going to AN lines here as the fittings will still be the same on each end, but it would look nice. 

[Skylynx]

11 hours ago, ghetdjc320 said:

It looks like the fuel filter rubber lines are not fuel injection lines as they look like they’ve bulged under pressure. Grab some 3/8 fuel injection hose and fuel injection clamps for those. The fuel rail rubber line could be replaced by AN fittings but you’ll need a 3/8 fuel rail fitting to -6 connector. The connection that is leaking is going to need to be severely cleaned. You can then use an ac/fuel line quick disconnect tool and hopefully get that rubber kine off the hardline. There won’t be much of a gain going to AN lines here as the fittings will still be the same on each end, but it would look nice. 

 Okay, so i should get the 3/8 fuel rail fitting to -6an connectors for the part of the fuel line that’s leaking?

is there somewhere you’d recommend me to get those? I don’t want to cheap out on cheap chinesium here since it’s the fuel lines, i don’t mind keeping the hard line parts, just replace the rubber parts with the adequate parts, i’m already ordering the 3/8th fuel injector hose to replace the ones coming from the tank and going to the filter!

[ghetdjc320]

2 hours ago, Skylynx said:

 Okay, so i should get the 3/8 fuel rail fitting to -6an connectors for the part of the fuel line that’s leaking?

is there somewhere you’d recommend me to get those? I don’t want to cheap out on cheap chinesium here since it’s the fuel lines, i don’t mind keeping the hard line parts, just replace the rubber parts with the adequate parts, i’m already ordering the 3/8th fuel injector hose to replace the ones coming from the tank and going to the filter!

I’d try to disassemble your current ones and make sure your tube fitting surface is still in decent enough shape to reuse. If it isn’t, you maybe need to switch to compression style tube adapters. Alternatively, If you have a quality 37* flaring tool that will work on 3/8 stainless tube, you can add an appropriate AN tube nut and flare the end. Earls and Fragola have been my go to for AN fittings and hoses respectively.

[llhat]

@ the fuel filter..   yes,  fuel injection rated hose,  and ditch the worm clamps...    dorman has some fuel injection clamps in the 'help' section... they do not cut into the line 'quite as bad' ...  the worm clamps tear em up.

 

[Htchevyii]

Here's how I replaced mine on the MJ and XJ.

 

https://youtu.be/TLPQEVPmYdk?si=Md9ZuM77b4bNRm0J

[Skylynx]

On 7/9/2025 at 3:26 PM, ghetdjc320 said:

I’d try to disassemble your current ones and make sure your tube fitting surface is still in decent enough shape to reuse. If it isn’t, you maybe need to switch to compression style tube adapters. Alternatively, If you have a quality 37* flaring tool that will work on 3/8 stainless tube, you can add an appropriate AN tube nut and flare the end. Earls and Fragola have been my go to for AN fittings and hoses respectively.

I think that’s what i’ll end up doing, i’ll get under the truck and tear everything out and see if i can reuse the tubes at all, if i do i saw these in amazon that i think could work, apparently these slide over the tubes and you tighten the half nut over them to compress it into a new a new AN thread fitting after which you can add a hose, i’m guessing these are the compression ones you meant?

[Skylynx]

On 7/9/2025 at 4:14 PM, llhat said:

@ the fuel filter..   yes,  fuel injection rated hose,  and ditch the worm clamps...    dorman has some fuel injection clamps in the 'help' section... they do not cut into the line 'quite as bad' ...  the worm clamps tear em up.

 

Already ordered the fuel injection hose clamps and the hose itself too! Thanks for the tip, i’m definitely ditching these ones it’s got right now

[Skylynx]

On 7/9/2025 at 8:12 PM, Htchevyii said:

Here's how I replaced mine on the MJ and XJ.

 

https://youtu.be/TLPQEVPmYdk?si=Md9ZuM77b4bNRm0J

Oh wow i actually watch your videos all the time! Your setup is pretty close to what i want to get to with mine!

As ingenious as the solution in the video is i think i would rather try and replace things with the AN fittings, it’s the little steel crown with the tube that you reused that’s leaking for me, i’m hoping it’s just the o-rings and not the piece itself, though as i said i’m going to replace everything with new connectors and hose anyway

[ghetdjc320]

Nice video, I’d be concerned about not having a barb for the clamp though. I tried doing that in my YJ and even used two fuel clamps but it still came off after a few hundred miles spraying fuel everywhere. This was on a 58psi line pressure system though so I’d expect it to last longer with the lower MJ line pressure. If you have an appropriate size hydraulic crimper though, you could slide on a new steel ferule and crimp it down. 

[Eagle_SX4]

3 hours ago, ghetdjc320 said:

Nice video, I’d be concerned about not having a barb for the clamp though. I tried doing that in my YJ and even used two fuel clamps but it still came off after a few hundred miles spraying fuel everywhere. This was on a 58psi line pressure system though so I’d expect it to last longer with the lower MJ line pressure. If you have an appropriate size hydraulic crimper though, you could slide on a new steel ferule and crimp it down. 

You can buy brand new hose ends with barbs on them from dorman. They are available in both 3/8 and 5/16. They look a little different but that is because they have tool less clips and can be removed with out any fuel line fitting tools.

 

https://www.dormanproducts.com/p-16452-800-121.aspx

 

https://www.dormanproducts.com/p-24796-800-120.aspx

 

 

[Htchevyii]

An AN solution would be ideal for me! So far, no issues with the clamps on the XJ or MJ. I would feel better if there was a barb though.