Fuel Dripping Off Front Diff

[JDillon]

I noticed a small puddle under my '09 2500 a couple weeks ago and checked it out. I thought the front diff was leaking at first because I saw that it was wet and there was a drop formed on the bottom. I didn't have much time to check it out that day, so I just dropped it off at the dealer since it's still under warranty. They said that it's diesel fuel and that it's normal for the engine to purge fuel above the diff. I haven't climbed up in there to see exactly where it's coming from yet. It's continuing to leak all over my driveway. Is this normal?

 

[Newt]

If my 09 has done it in 19000 miles, I sure haven't noticed.

Newt

 

[mpaulson]

During the last two winters, I have had fuel drip from the CP3 pump. I haven't looked very hard to try to see where exactly it comes from, but it only does this when it is cold. Well below freezing type of cold. It has never left a puddle, but it does wet the diff cover and I can smell it a bit. As soon as it warms up a little, it goes away. I took it into the dealer ship to have them look at it since it would unoffically be under warrenty, the service guy didn't have the balls to call me, he had the manager call me to tell me that it would be $3600. 00 to fix it. I told him to shut the hood on his head and insert the tail pipe where the sun don't shine. I had read that it is either a plug on the back of the pump that can be resealed or the FCA valve, which can be replaced on it's own. Dodge changes out the whole pump rather than repair the cheap componants. I'm still running that pump with no problems yet and I expect to smell it again when the mercury drops to well below freezing. 120,000 km's on it. It's not a wonder that the auto manufacture's are in trouble with repair procedures like that. What a waste of money.

 

[JDillon]

Based on what you guys are saying, it doesn't sound 'normal' to me. It's been in the 80s and 90s here, so certainly not anywhere close to freezing. I made sure that the service department noted their findings so if something goes wrong, I can pin it back on them. I'm going to get up under the truck and check today or tomorrow to try to pinpoint exactly where it's coming from. I know it's not coming off the fuel filter, but I can't see exactly where it's initiating- looks like the driver's side of the engine somewhere from looking down from the top and in from the driver-side wheel well, but I can't tell exactly where. The mechanic said that the 6. 7 has no way to 'recycle' fuel if necessary, so it will occasionally 'purge' fuel. I have no clue what he's talking about.

 

[Hoefler]

Make sure the drain in the fuel filter is tight. The drain tube drains on the front diff.

 

[JDillon]

The drain tube and the fuel filter were the first thing I checked. They're both bone dry, so I know it's not coming from there. The last time I purged the filter was about a month ago now, so I'm pretty sure it's not still residual fuel from that either.

 

[Jim W]

I have nearly 36K on my truck and I have never had fuel leak from my CP3 pump. I have experience +100 F too -25F temp's in the last three years of ownership with this truck. I know this would be a real big issue with all of us members with a 6. 7L engine if fuel leaked from the CP3 like your dealer suggested.

I would recommend that you find a new dealer and have them look at the CP3 pump, or fuel fittings that maybe leaking in this area.

Jim

 

[JDillon]

I got up under the truck on my creeper and for the life of me, I can't figure out where the heck the fuel is coming from. The diff is soaked from top to bottom with diesel. Everything above the diff seems completely dry. The only thing I can think is that it is, in fact, coming from the fuel filter, but like I said, the filter is dry and so is the drain tube. I started the truck and let it idle for a bit while I was up under there and didn't see any dripping from anywhere. I did loosen and retighten the purge valve on the filter a few days ago thinking that might be the problem. Maybe it was and the dripping for the past couple days was just residual fuel on the pumpkin. So I wiped the diff down from top to bottom and I'm going to see if there's a new puddle in the morning. I've got a service appointment set for Thursday in case it's still dripping tomorrow.

 

[TLane]

I'll call BS on the dealer for that one. Any fuel leaking anywhere is a big no-no. Not only is it wasting your fuel and it's creating a toxic waste site, it's also a fire hazard. Even if diesel fuel doesn't ignite like gasoline, it's still a fire hazard. And, it will most likely get worse, whatever the problem is. I'd recommend finding another dealer if possible. If not, I'd threaten the dealer with calling the EPA and the NTSB about it. No vehicle should ever "purge" or leak fuel of any kind. And yes, the 6. 7 DOES have a return line back to the fuel tank.
Likely candidates are the VP44 high pressure fuel pump, the fuel filter, or a line to an injector.

 

[TulsaOkie]

My thought is maybe a injector line or pin hole in return line, I had a 5. 9 and #5 injector line would give me fits. Line would vibrate loose and then break, shooting fuel everywhere. 334k on this truck and proud to say "No Drops or Leaks".

 

[JDillon]

After retightening the fuel filter purge valve and wiping down the diff pumpkin, I let the truck sit for 24 hours. No puddle on the driveway and no drop formed on the diff. I just drove it to work though and now it's dripping again. As soon as I stopped, I reached in and felt the fuel filter. There was a drop of fuel on the bottom of the drain tube, so I think it's probably just fuel getting past the purge valve seal on the filter while I'm driving. Even though I tightened it all the way down as tight as I can, it's still leaking. The fuel drips down and builds up on the diff and then slowly works its way down and drips off the bottom. Before, by the time I was checking the fuel filter and drain tube, it was already completely dry.



So, I think I've found the problem. It's time to change out fuel filter anyway, so I'm going to knock that out and hopefully that's all it was. Thanks again to everyone for their comments. The mechanic at the dealer was definitely full of it though.

 

[CUMMINZ]

A while back the oil line connector off the top of my spin on oil filter had a very very small leak. It showed up on my rear end pumpkin as a film of dirty oil. I thought some how the rear diff was leaking. After I fixed my engine oil leak and washed off the rear pumpkin it then stays clean. Go figure.

 

[JDillon]

I took it to the dealer today. They apologized for the other mechanic feeding me a line of bull. The tech today was on it though. Like I thought, the drain valve wasn't sealing properly. They replaced the entire fuel filter assembly because there's a newer version out. No leak now. Thanks for all your help.