Engine/Transmission (1998.5 - 2002) Diesel Fuel Leak - Ideas?

[BBates]

Problem: Fuel Leak. I have a 1998 24 valve Dodge with about 51,000 miles on it. I began to notice a drop of fuel on the floor of the garage after I'd drive the truck. Approximately right between the front wheels and a bit to left of center. I took the truck to my favorite mechanic and he tightened up everything. All fuel lines. Drip stopped; momentarily.



Two weeks later, I was pulling my camper to Odessa, Texas for the CAF AirSho held down there in October. By the time we got to Raton, N. M. we thought we could smell diesel in the cab, and that night when we camped there was a small (about 2-3" diameter) spot under the truck. By the time we reached Lubbock the next day, we were sure we smelled diesel. We camped the next night in Lubbock, I could see a drip on the grass, so I went to the local Dodge dealer, and they said, "you have a loose supply line to the injection pump. " He tightened it up, I washed the truck including underneath it, and everything was fine - no smell - until we started back from Odessa. By the time we got to Amarillo, we could again smell diesel, and there was a spot on the ground again. Reached Raton that night, there was a large spot on the gravel, next morning.



We made it in to Highlands Ranch, the next day, and I again took the truck to my mechanic. I asked if they could again tighten the lines, and maybe use Loc-tite or safety wire on them, to be sure they stayed tight. They used 'Loc-tite' instead (which I've used on the diesel in my boat, with great luck) and again all was fine. Drove to Fort Collins and back (~250 miles), and the drip is again back. James (mechanic) swears lines are tight.



IF anyone has any suggestions on where this is dripping from and how to stop it I'd really appreciate hearing from them? Any suggestion on how to fix this (other than using witch doctors) would be welcome. I'd even consider a witch doctor, come to think of it...



It is driving me crazy and camping season is about upon us again.





Bill Bates, CPP

Retired and LOVING it

 

[Steve St.Laurent]

If you find it let us know because I'm pretty sure it's going to be a growing problem. I have a leak on my 98 as well but it isn't enough to be able to tell where it's coming from but I can smell it and now I'm starting to leave small traces on the ground. I'm pretty sure it's seals shrinking due to the ultra low sulfur diesel fuel we are now on. Fuel leaks was one of the expected outcomes. I doubt you'll get it taken care of by simply tightening fittings. More likely that the seals will need to be replaced - hopefully they aren't ones inside the VP44 that we'll have to buy a new pump for.

 

[Bob4x4]

You can add a flourescent dye designed for engine oil leak detection. If you can not find that use ac dye for an r12 system do not use dye intended for r134(pag oil will not mix well) then use a black light to see where the leak originates from.



Bob

 

[turbo torque]

I too have a 98. 5 that has a developed a Drip! I can see a trace of fuel under #3 injector line at the head.



Having the head off, changing injectors, and cracking #3 to bleed to bleed air a few times, I'm thinking the tubes to the injectors might be leaking small.



It,s not a visible leak, just not dry. Some times I have hard starting issue, like there could be a little air. Gonna try a new SET of tubes. I've herd our tubes on early 24v are prone to leaking. Check the lines by the head for moisture. Good Luck, and let us know.

 

[Bobalos]

My injection tubes were leaking @ the head when I fist bought it & I could not really see it. I tightened them all up & no more problems.



There are gaskets on those fittings. Personally, I would not put loc-tite on any of them.



Bob

 

[Hendricks]

While i wish i could give you a specific answer all i can tell you is that i had the EXACT same problem. Changed out my injectors for the jammer 5s and havent seen a drop since. Im fairly sure that mine was coming from the back of the head or #6, and I had tightend all of the fittings several times with no positive results.

 

[JAG1]

I second the recommendation to never use locktite on fuel fittings.



I had a leak like your talking about on my first gen truck. It was a banjo bolt that was very easey to take out and add new sealing washers. The sealing washers only cost some pocket change per pair, it takes two per banjo bolt.



On my second gen truck I was amazed by the difference in getting rid of these restrictive banjo bolts and going to the Vulcan performance big line kit with pump relocation. Really helps keep the VP44 cooler with more fuel volume.



If you don't want to do Vulcan the big line change, I would not keep tightening things as you have been... ... ... I would change the sealing washers that have the little rubber seal. They are too easey and you won't have the possibility of over tightening things.

 

[DWest]

Return line T

Mine was leaking at the back of the motor where the return line from the injector pump and the return line from the back of the head meet at a T going to the tank. There are 3 little black rubber gromets in that fitting that had started to break down. They're about $8 bucks each. DW

 

[ACoyle]

Is there a fuel heater in the canister? Mine cracked. Leaked a while Odor drip kind of stuff. Then finally became a fountain. Just a thought - AC

 

[obert]

definately replace seal rings onany suspect fittings.



As far as the supply line leaking, mine had the line from filter head to the pump sart to leak, it turned out the tube was cracked where it enters the banjo, or starting to separate from the banjo. The shop brazed the tube to get me going, but ordered a new tube assy. , just in case, as we might consider that a half-assed repair. But that often works, and years later the new tube is still hanging in its original bag in my garage..... Of course, the vulcan kit got rid all the inlet tubing.

 

[WNasser]

Just a thought

I had a problem the crush washers for the banjo fitting on the return line from the injection pump were the cause for a leak on my truck. As much as I tightened the lines down, there would still be a leak. The stupid rubber seal on those things disingrated. I would say look at those if you haven't already.

 

[JField]

Check the wiring cluster where it goes into the top of the fuel filter mount. Mine had a leak there and was very hard to detect. Finally found it using a flashlight and looking up from under when it was dark.

Fixed it by removing the mount, the 3rd lift pump and installed a FASS and all is good now. Hope this helps

Good Luck

 

[RustyJC]

Check to see if the leak is coming from the lift pump - Cummins Early Warning.



Rusty

 

[WBodine]

I recently had a similar drip could not find it to save my life. . I finally found that #5 injector had a small leak, after suspecting my injector lines. . Got it good and tight thought I had it fixed. "WRONG" After some serious hair pulling I found it was also #6 injector leaking. This is a major pain to find leaking and a bigger pain to get good and tight. #@$%! Fixed mine I hope this is some help to you.....

WBodine

 

[Sean Flanagan]

I had a 98. 5 with a similar problem at around the same mileage. It turned out to be the low pressure line between the fuel filter and the injection pump. The Cummins guys said it was a common problem and had an updated part number for it at that time.



Sorry, I don't have the part number, or the truck anymore since I recently sold it with 270k miles.

 

[Bob4x4]

I had a 98. 5 with a similar problem at around the same mileage. It turned out to be the low pressure line between the fuel filter and the injection pump. The Cummins guys said it was a common problem and had an updated part number for it at that time.



Sorry, I don't have the part number, or the truck anymore since I recently sold it with 270k miles.

The line you are referring to was a hard line with a union in it. They were replaced by the current version. (recall)



Bob

 

[Sean Flanagan]

Yes it was a hard line. There was a small crack where the tube is welded into the union.

 

[DSpencer]

Check to see if the leak is coming from the lift pump - Cummins Early Warning.



Rusty

You pegged the one I have just found. I have a small leak at the base of the lift pump. The first indication was a blown fuse on the starter. Replaced the 20 amp fuse and looked at the starter. It was wet with diesel. I saw a slow drip coming from the connector of the lift pump. I am guessing that I need a change.



Any recommendations or where to buy? I have a Cummins here in Arlington but the price, the price.

I hate to do this as this is the second pump I have had on my truck. It has over 134 thousand and the first was replaced under warranty around 50k. I guess I have been lucky. .