Dropping the Fuel Tank

flman

Roadrunner, Genius of Birds ALWAYS WINS! NO FAILS!
Flman,
I have done the same thing with other lines and brake lines on other models. Practical re-routing makes perfect sense to me. :cheers:

What model year and location are you that the brake lines went bad? I presume they rusted? So far my 2004 in the northeast seems to be looking OK. (knock/touch wood) vic
05, upstate 90 miles north of NYC. Yup they rusted out, pretty common around here. They usually go bad at the mounting clips, because that is where the debris builds up.
 

brassarl

2006 T1N 2500 Long & Tall
the temp was 104F and it was then I noticed a puddle under the fuel tank. Immediately I released the fuel cap pressure. Fast idled for about 45 minutes, needed to charge batteries anyway. Of course the bottom of the tank was still wet.
A few weeks later here's the rest of the story. The fuel leak never cleared up. So took it to a Dodge/Sprinter Dealer and they ordered a new gasket and nut for the top of the tank (total parts $24) The total bill for the repair... just shy of $700. I had purchased an extended warranty that covered the repair minus $200 deductible. As is described in other posts, run the fuel tank near empty and drop the back end of the tank to access the repair. Here is the parts list for my 2006. Item 1 & 2 is the required parts!! The mechanic told me there is a pressure release overflow but because the nut was loose and some grit had gotten under the gasket, that was the weak link in the overflow protection.
 

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Oxymoron

New member
I know this is an old thread but was wondering if there is concern for getting air in the lines? I need to drop the tank to clean it of algea. I had trouble with air in the lines when I changes my fuel filter and don't want to have the same problem.
 

220629

Well-known member
I know this is an old thread but was wondering if there is concern for getting air in the lines? I need to drop the tank to clean it of algea. I had trouble with air in the lines when I changes my fuel filter and don't want to have the same problem.
There's no real concern with getting air in the lines if your fuel system is leak free.

Not that you asked...
I would suggest that if you presently have no problem with air in the lines or a plugged filter I would not disturb the fuel filter components at all during the tank cleaning.

Once the tank is cleaned and refitted I would run the old fuel filter for a time. Carry a spare fuel filter and tools to change it in case.

The reasons. If there is any disturbed dirt left over in the tank then the old filter will get it, not the new one. If there are any air leaks after the job then it is safe to assume that the problem is in the lines that you disturbed and not the filter components.

An alternative would be to install a new filter and establish no air in the lines before dropping the tank. Either way I wouldn't disturb both the fuel filter and tank at the same time.

:2cents: vic

Added:
BEFORE anyone needs to drop the tank, grease the strap studs and nuts. Even after the fact grease will soak in and help to release the rust. I just use heavy duty wheel bearing grease. Some recommend anti-corrosion products.
 
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Oxymoron

New member
Ok. I just had to replace the filter last week because of the contaminates. Was on the freeway and it would go past 35 and the dash light came on. Didn't have spare and had to limp 20 miles to Mercedes dealer who raped me and caused more leaks. Very frustrating. I asked for fuel sample and it was pretty bad. So I figured I would drop the tank to clean it. Thanks for the response. These Sprinters are very finicky. Been working on and building cars/bikes my whole life and can seriously say that these are a different animal. Still nuts and bolts but man!
 

PATECO

Member
OK guys and gals, now I too have a fuel tank leak as of today. I was driving down the highway and noticed a diesel smell that would not go away. Was worried I had a high pressure leak under the hood, so I pulled over, left her running, and popped the hood. No fuel smell. I walked around the truck, and saw fuel spray on the rear windows. I looked under neath with her still running and saw substantial quantities of fuel dripping off the bottom of the tank. I was worried that I had thrown up some debris on the highway and holed the tank. I shut her off, and climbed underneath. (I still smell like diesel LOL) With the truck turned of the leak slowed and stopped. So no hole in the bottom. I had less than half a tank of fuel in her. I turned the ignition on, but did not start her back up. The fuel leak instantly returned dripping off the top of the tank and down the side.

What the heck do you think has broken, and how do you suggest I fix it?

She is a 2004 Freightliner 2500 with 298,000. miles

PS: She runs fine even with this leak. Turned around at the next exit and made it home and shut her off with no performance issues. She and I just stink of diesel. There is however a small puddle of diesel on my concrete driveway from before I shut her off.
 
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flman

Roadrunner, Genius of Birds ALWAYS WINS! NO FAILS!
Ok guys and gals, now I too have a fuel tank leak as of today. I was driving down the highway and noticed a diesel smell that would not go away. Was worried I had a high pressure leak under the hood, so I pulled over, left her running, and popped the hood. No fuel smell. I walked around the truck, and saw fuel spray on the rear windows. I looked under neath with her still running and saw substantial quantities of fuel dripping off the bottom of the tank. I was worried that I had thrown up some debris on the highway and holed the tank. I shut her off, and climbed underneath. (I still smell like diesel LOL) With the truck turned of the leak slowed and stopped. So no hole in the bottom. I had less than half a tank of fuel in her. I turned the ignition on, but did not start her back up. The fuel leak instantly returned dripping off the top of the tank and down the side.

What the heck do you think has broken, and how do you suggest I fix it?

She is a 2004 Freightliner 2500 with 298,000. miles
Sounds like one of the hoses are leaking?
 
There are hose clamps that don't cut into the rubber. They should always be used anywhere possible. If you have any of these, they should be replaced. An easier solution for this issue is obvious. Use the correct hose clamps to begin with. Thanks to all here.
 

220629

Well-known member
I've successfully used clamps similar to the one shown many, many times, but I do agree that a completely smooth inner ID type clamp is better.

That vertical brass colored piece was added and unnecessary. I don't understand why it was put together like that. :idunno:

vic

HoseCrimp.jpg
 
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PATECO

Member
OK it started leaking again last night, so the hose must be rotten. I will drop the tank again tonight and replace the whole section of hose.
 

benstoddard

2006 110k 158WB
Hey all, I recently dropped my tank to replace the fuel pump seal that was causing a leak, as well as install a standpipe for a diesel heater. I reinstalled everything and when I started it up, my fuel gauge showed that the tank was empty. I thought maybe it was because I spilled some diesel during the process, so I filled it up with 8 gallons and still it shows that I am fully out of fuel. Any thoughts on this?
My only hunch is that I installed the yellow pump module incorrectly: it has an arrow that lines up with another arrow on the tank, when tightening the plastic nut around it, I made sure that the yellow module's arrow lined up with the fuel tank's arrow (this took some trial and error as the module would spin with the nut, so I had to guess where the module arrow was going to end up after tightening fully). After awhile of frustrating trials, I got it almost aligned and said f**k it and reinstalled the tank. My hunch is that maybe the two arrows needed to be aligned perfectly and weren't aligned enough in my case. Here's a picture that points out the arrows on someone else's tank, and a black line approximating where my arrow is pointing.
Screen Shot 2021-05-11 at 6.36.32 PM.png
Sorry if this is confusing, let me know if anyone has any ideas!
 
great write up but sadly I am not finding it easy to remove the flexible rubber hose between end of filler and tank. I think it has hardened over the years and cannot get it squish up to clear end of tank and remove. I would need to get it from Germany apparently, 5 weeks wait!
 

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