Engine/Transmission (1994 - 1998) Dropped Fuel Tank - what I found

[guldam]

Dropped the tank. Hardest part so far was trying to get off the fuel send and return connectors and the wiring connector. Figure that out and didn't break anything.



Tank was about at 1/8 tank of biodiesel, and it's still heavy as all get out... and I'm feeling weak. eeep.



Anyway the fuel sending unit was supposed to have been replaced about six months before I got the truck. The tank was supposed to have been dropped, and flushed also. I see no evidence that this thing has ever been off. no other finger prints other than mine, and I saw no screw driver marks on the fuel sending threaded ring. Interesting. I think the previous owner got ripped off.



Anyway the bottom filter on the sending unit has a rather lovely layer of black tar like material, and I also found it lumped up and nasty looking on the inner filter.



Wondering how to get this stuff off, or am I just going to have to order new filters (assuming they sell them separately. )



Any idea if it's safe to throw these things in the dishwasher (when my wife isn't looking that is)?



Will drain tank tomorrow, and see what's inside.



GulDam

 

[guldam]

Oh, and is the hose barb circled in yellow supposed to have a hose attached? or be capped off?



GulDam

 

[B.G. Smith]

I doubt that soap and water will cut that stuff. I would try something like carburetor spray cleaner or maybe acetone. bg

 

[guldam]

I tried scrubbing with a toothbrush and biodiesel, but no go...



This stuff acts like it's baked on.



GulDam

I doubt that soap and water will cut that stuff. I would try something like carburetor spray cleaner or maybe acetone. bg

 

[JJPage]

Oh, and is the hose barb circled in yellow supposed to have a hose attached? or be capped off?



GulDam

On my 3rd gen I attached a small length of vacuum hose to those barbs(i had 2) and stuck them farther up in the frame, not sure why Chrysler left those vents open like that.

 

[Missouri Mule]

guldam, That's your pressure relief/rollover valve. No hose from facory but they would leave a cap on it accidently now and then.

Running a hose up higher mite be a good idea if you are going thru high water.

 

[toms73novass]

brake cleaner took care of my gunk. Didn't hurt the plastic.

 

[guldam]

Update

Update:

Soaked the two filters in SeaFoam fuel treatment overnight, figuring that a fuel treatment that makes all sorts of claims to getting rid of everything from sludge to carbon to baldness, would do the trick.



NOT.



So this morning I liberally applied some spray carb cleaner, and then let it soak. Swished around for quite a bit, and it did a fairly good job of getting rid of the worst of the crud. Not good enough. So then I got some Methanol from my stash, and soaked the filters in that. That DID the job. I just hope I haven't softened the plastic.



Up next drain the fuel tank of the bio, and run it through a 5 micron, and then a 1 micron filter and see what the inside of the tank looks like.



I think what I am seeing is a combination of asphaltene (tar like substance), left over fungus, and particles of crap from the bad batch of BioDiesel I got last year.



Wonder if any of the fuel lines are partially plugged with any of this crap.



I like fixing things, and I like it when I my suspicions of funk in the tank are true. I will rid the fuel system of this stuff, and be even happier.



GulDam

 

[guldam]

Another Update

Put the fuel sending unit back together all nice and clean.



Then I pumped out the remaining 8 gallons or so of BioDiesel. Used shopvac to slurp out a couple white sludge bits, which I think are probably congealed, Biodiesel or diesel and water. Tank looks clean other wise.



Ran the pumped out Biodiesel through a 5 micron filter 3 times since I couldn't find my 1 micron sock filters. Pumped it and a bunch more Biodiesel into the tank.



Started it up and truck seems to run a tiny bit smoother, though it really wasn't running rough before. Truck hauls butt up the hills around here, and I'm safely and quickly able to leap on the freeway.



Life is good.



Now I need to find a needle valve so I can reinstall my replacement Marshall fuel pressure gauge.



Some more pictures from the effort, including one image of one of the two straps I used to hold the tank in place when I dropped it, and when I reinstalled. They prevented me from hurting myself and made the job easy.



GulDam

 

[guldam]

More images:

 

[budnate]

Nice, what day can I drop mine off for the same treatment?



B.

 

[bheiting]

Oh, and is the hose barb circled in yellow supposed to have a hose attached? or be capped off?



GulDam

That vent should have a filter on it. Apparently Chrysler figured if you can't see it, don't worry about it. The dealer has a filter kit I believe, or you can go to your local auto parts store, buy a cheap fuel filter, and a short length of hose.

 

[The patriot]

Looks like mine did last fall when I had it apart. Except my plastic has a yellow/reddish tint. :-laf

 

[SLangone]

Nice work! I did this last weekend but instead of dropping the tank i lifted the bed far back enough to remove the assembly so that I could replace with new because the old one had rusted threw were the 2 metal fittings bend. You may want to consider replacing the fuel filler neck. After further inspection I notice a small pin hole leak when I fill my tank up. Great job getting her clean I had to spend 300 bucks for the assembly (from Napa). By the way how do you like using Biodiesel?

 

[fox]

Dropped the tank. Hardest part so far was trying to get off the fuel send and return connectors and the wiring connector. Figure that out and didn't break anything.



Tank was about at 1/8 tank of biodiesel, and it's still heavy as all get out... and I'm feeling weak. eeep.



Anyway the fuel sending unit was supposed to have been replaced about six months before I got the truck. The tank was supposed to have been dropped, and flushed also. I see no evidence that this thing has ever been off. no other finger prints other than mine, and I saw no screw driver marks on the fuel sending threaded ring. Interesting. I think the previous owner got ripped off.



Anyway the bottom filter on the sending unit has a rather lovely layer of black tar like material, and I also found it lumped up and nasty looking on the inner filter.



Wondering how to get this stuff off, or am I just going to have to order new filters (assuming they sell them separately. )



Any idea if it's safe to throw these things in the dishwasher (when my wife isn't looking that is)?



Will drain tank tomorrow, and see what's inside.



GulDam

That looks like glyerine.

 

[guldam]

I agree that some of it at least looks like glycerine.



There was the shiny black stuff that looked like glycerine. It was soft and easy to remove.



There was another bit of black that was rather stringy, and I assume to be residual fungus from a year and half ago that the previous owner fought and paid for.



After removing all of this, there was a layer of HARD black stuff that I could not scrape off with my finger nail or a tooth brush even after soaking over night in SeaFoam (which appears to be absolutely worthless as a fuel system cleaner. ) Then there was a bit of brown and green residue.



Carb cleaner removed some of the hard layer, but left a good portion, and also left the brown and green residue that was mostly in the screen openings.



Methanol cleared it all up in short time. Glycerine will be dissolved into the BioDiesel when there is Methanol present I believe. But beyond that I'm not entirely sure of confident what all the crud was.



I think that in six months I'll drop the tank again and take another look. I'm curious, and since I've essentially started from scratch with a "clean" fuel system starting at the tank, I'll be very interested to see what the tank looks like in six months.



I must say that I was pretty pleased that I did not find a big thick layer of coagulated glycerine and fryer bits at the bottom of my tank. That one bad batch of BioDiesel made me a bit worried.



Even though I recently changed out my fuel filter, and cleaned the pres-heater screen, I think I'll change that out too. Rig up my fuel pressure gauge and see what it says.



This was one of the more satisfying maintenance/fixit projects on the truck.



GulDam

That looks like glyerine.

 

[stumphumper]

I read somwhere that colemen campstove fuel is the main chemical cleaning stuff that is in most of the fuel cleaning products. It's a heck of a lot cheaper cost to do some your dirty cleaning jobs. 2cents

 

[The patriot]

Coleman fuel is about $9 gal around here.

From what I understand, it's gasoline w/o the additives.

 

[crasher]

Nice work! I did this last weekend but instead of dropping the tank i lifted the bed far back enough to remove the assembly so that I could replace with new because the old one had rusted threw were the 2 metal fittings bend. You may want to consider replacing the fuel filler neck. After further inspection I notice a small pin hole leak when I fill my tank up. Great job getting her clean I had to spend 300 bucks for the assembly (from Napa). By the way how do you like using Biodiesel?

I did it the way you did above so I could replace my leaking break line.
That was a fun job too.
I replaced my sending unit at the time, and my tank was remarkably clean inside.

 

[HEMI®Dart]

Nice work & Write-up!

guldam, Nice work & Write-up! Was your rear fuel tank hanger rusted? Not sure where you live. Mine had rusted through & broke. I told my co-worker to check his a '95 RAM 1500. It broke 2 days after I told him to check his.