Draining fuel tank

Does anyone have a method to drain out their fuel tank? I have half tank of ~6-7 year old diesel in my tank. I just got my started replaced and know that she cranks, but i did not want to try to start any further til i could drain the tank. I got a bottle of diesel conditioner to hopefully break down any sludge and poured it in.
After that sat a while, I took some rubber hose and connected it to a little 12 V fuel pump, inserted as far as i could into the tank but could not get it to reach and nothing came out.
I know the filler neck runs above the rear pass tire, then there is a tube that runs horizontally under the "bed" and then dips down into the fuel tank. I think going in from the gas cap is preventing me from making it all the way to the fuel in the tank.

Is there a easy-ish way to remove that filler neck and tube so that i can stick my hose into the tank at a much closer distance?

Also, I know the filler neck is replaceable with the civy version so you can use civilian gas caps - what about the tubes that run from the filler neck into the tank? Anyone replace those?

Soon as i can drain the tank, my plan is to do a quick oil and filter change, new fuel filter and put in a few gallons of fresh diesel and crank til she hopefully turns over. After I know she's turns over, I'll replace the injectors and glow plugs as well as hoses and anything else that needs freshening up.

Isn't there a steel line that stops at the frame rail that is capped off? My m1009 has one. That should be easy to hook up to and drain the tank.

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I think they all had 3 tubes on the pickup in the tank, with a plug on the third. I think it was used for heaters etc. You could take the rubber plug off and hook a line to it, then siphon it out. That's what I did.

Picture for reference

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I almost couldn't see it cause it was in such bad shape - but got it off and started the flow.

Thought the 7 year old diesel would look worse than it is - a urine color. better safe than sorry i guess.
thanks everyone!

As long as it doesn't have water, mold, or debris I'd run it and not worry about it.

Skinny said:

As long as it doesn't have water, mold, or debris I'd run it and not worry about it.

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Well not knowing exactly how long it had been in there I didn't want to take the chance of running bad fuel in there to maybe complicate things later. my mechanic buddy thought it'd be a good idea to get some fresh oil and fresh fuel in there before i went trying to turn her over. he's a diesel mechanic for the county fire depts and ambulances, so I trust his judgement.
I will say it's been killing me not knowing if this truck will actually turn over. Ive had in in my driveway since late Feb and just managed to get the 2 alternators replaced and the starter since it wouldn't even turn over after a fresh set of batteries. I'm pretty confident she'll turn over with enough sweet talk. Cant wait - all be all smiles that day.
Tomorrow I'm draining the oil, replacing filter and oil, replacing fuel filter, add 5 gal of fresh fuel along with some tank cleaner (Star Tron).

Not sure if anyone mentioned it but that auxiliary tap into the fuel tank will only draw the fuel tank down to a 1/4 tank. That was a smart thing to let the vehicle have a 1/4 tank so you could drive and get more fuel if the equipment you were running off the tap ran out of fuel. Good Luck. It may be a good idea to drop the tank and change or remove the fuel sock on the end of the pick up tube of the sending unit. 40 years does a number on filtration parts. Take Care.

I did not know that. I thought i saw a post on the site that someone mentioned that the port is used to get water out of the tank if needed and that the tube on the inside went to the bottom.
I see you have worked on several tanks, so you know better than me.
Yes I do want to get the sending unit serviced and get a new sock, but that's a wee bit out of my skill range.

You can do this. I can talk you thru it. No rocket science. Lets do it.

I could be wrong about the 1/4 tank auxiliary tap. But yes you can drain it that way for sure. I forgot more things in the past 5 years than I care to admit. But I install generators on Ford trucks and the pickup tube only worked till 1/4 tank. Chevy generators were the same in G an P series vehicles I worked on. But I think you can drop the tank and change the fuel sock. Even eliminate it. Basic hand tools is all you need.

SUCCESS!!

Got the oil drained and refilled, put 5 gal fuel with some StarTron and decided to go ahead and try to fire her up.
Took little over a dozen attempts, but she finally turned over and stayed on. I felt all tingly for a few minutes sitting in there.

I let her idle for a good 15 minutes and noticed that every time i pressed on the gas, whenever I let go, it died and I would have to re-start.
Guessing that may be some sort of throttle cable/linkage issue maybe?

Tomorrow I need to get my alternators installed, but i am not sure of the wiring connections - does anyone have a picture or diagram of what cables go to what posts on the alternators? My driver side is not ground isolated (Autozone model) so will there be a wire left hanging on that side?

Then maybe this weekend I'll have time to flush and drain the cooling system and get new hoses and thermostat in there (and heater core hoses).

cucvrus said:

You can do this. I can talk you thru it. No rocket science. Lets do it.

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Actually I may take you up on that when the weather isnt raining every day here since I'd be doing this in my driveway. I found the replacment sock on Amazon of all places and got that ordered. Figured get it now since I'm sure I will need it.

Get started by spraying penetrating oil on the rear strap nuts. They are on a 7/16" stud. You will need an 11/16" wrench to hold the bottom nut while you loosen the top nut. An impact works great to shock the nut and loosen it quickly. Do not force it or hammer on it with the impact. Show some pictures so I can see what we are working with. Good Luck. If you have a spare tire remove that a while. It will help you in getting the tank down.

If it's dying when you throttle up there is probably a fuel delivery issue or injection issue.

I think that extra fuel line only goes to a 1/4 tank. I think it's for a fuel fired heater. I remember seeing that when changing the sending unit.

I recently had to drain my tank due to contamination. Have a look at this thread - https://steelsoldiers.com/threads/hard-start-issue.207027/

I disconnected the fuel supply line coming up to the fuel filter and, after cobbling together a line that would fit, I managed to hook it into my manual siphon pump and emptied my tank that way. I would have just dropped my tank, but I have a class iii/iv hitch installed and it is a bit more of an involved process to drop the tank.

Make sure you bleed the air out of your system after you are finished with repairs, including cracking each injector until you see a tiny bit of fuel coming out. Oh, and pulling the glow plugs out for the time you are cranking her over to bleed everything will make rolling the engine a lot easier and help save your batteries and reduce time on the charger.

After all this and you truck does run right, you may have an IP issue.

I did mine and I am no master mechanic ! Good luck !

ssdvc your batteries are living on a hope and prayer. Low amperage is hard on starters and CUCV's in general. It only cost's a few dollars more to go first class. WOW. I seen the price that people are paying for these CUCV's on GovPlanet. Crazy man crazy.

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I hear ya Rick, but I am not there yet. I do think this winter I will be ready for some new ones. Already located a shop that sells new Deka batteries in RI.