Dirty fuel tank.

Now that I know my Beast will run fine, I dropped the tank. I would guess it had between five and ten gallons of the nastiest brownish-orange, sour gas in it! I pulled the sending unit and emptied the bloody fool thing out the best I could. Any tricks to get the remaining pint or so out? It left a nice sticky varnishy finish on the sending unit. Is there something I need to rinse the tank out with, or will a full tank of clean fuel be enough to dilute whatever dregs are left? I've not tested the sending unit yet. It is pretty sticky and does not move freely enough to float. Hopefully it is salvageable. There are other things I'd rather spend the money on this truck than a new sending unit...

I still need to test the fuel lines along the frame. Will put a bit of air pressure to one end to make sure it is clear. If it weren't the middle of winter--and I didn't have an aversion to spending any more time than necessary on the ground on ice and snow--I'd go ahead and just run new lines.

As an after thought.... I've not dropped a lot of tanks over the years, but all that I have had a pad or barrier of some sort between the straps and the tank. In this case the straps ran directly against the tank. Is this normal, or do I need to put something in there when I remount the tank? The tank is plastic, if it makes a difference...

I used full strength Drain Cleaner in my M52 tanks and it polished them up very nicely. I took the sender out and soaked it in the same stuff and it came out clean as well. I then used Rustbullet to coat the interior of the tanks and the sending unit and I expect them to stay clean as long as the truck stays running

replaced sending unit

Hi. I am looking for the sending unit that fits the 77 M880 plastic fuel tank. Did you have to replace your unit? I can't seem to find one that matches the specs for this truck. I too am having to drop my tank and clean it. I am getting rust in the fuel filter. Since the tank is plastic, I am assuming the rust comes from the metal of the sending unit.
Any help or info appreciated.
Myles

I did replace it, and the tank. I've parts truck and both the sending unit and tank were in good shape in it.

Cool, glad that worked. Gives some help for my beast, currently nicknamed "Trouble".
I may have a lead on parts from a gentleman on here.

Enjoy your beast!
Myles

if you have a dirty tank, a quick fix is putting an additional fuel filter on the fuel line to the pump, close to the tank is best, takes a while but helps clean the tank good, moparperformance.com has sending units, i think thats the site, the units are like 150 bucks i might be able to get a few to sell for about 70 bucks a peice, im gonna check this weekend

Hi. If you can get a sending unit for one of these, I will definitely buy one from you. Every unit I have found has the wrong resistance values. That sounds to me that it would cause the fuel gauge to be inaccurate. I've also been looking for a fuel gauge with matching specs for the sending units and have the gauge fit the dash opening. It's like a 3 ring circus trying to get it all to match. Let me know how the search went. Thanks again,
Myles

i have a sending unit i took out of a plastic tank from last weekend, top has rust but the unit works, you may be getting wrong resistance values because of how its grounded, check your ground wire, currently my truck doesnt have a working guage because the ground is bad or the unit is shot, im gonna trouble shoot it this weekend i might go on a junk run and get some units to sell

fuel sending unit

Actually, I haven't tested mine. I meant the wrong resistance is the resistance ratings on the sending units I have researched to buy. I have not removed my tank yet. If careful with it, the truck works fine. Rust on top of unit doesn't matter me as long as all metal inside the tank is not rusted. My local yards laugh when I ask for a 30 year old part. Most aren't keeping parts for cars over 7 years old.

Let me know what u find this weekend, I know I need one. I don't want to pull tank for cleaning and not have a clean sending unit to put in. Thanks again.
Myles

RE: fuel sending unit

I spent the $100 Plus and got the factory one,
Yea it's pricey but it works fine & problem solved.

RE: fuel sending unit

Dont quote me on this.... But if I remember right I read on the PowerWagons forum where guys were taking sending units from other Mopar cars from the '70s ( like a Aspen or something ) and making the pickup tube and float rod a little longer. Apparently the sending unit is the same other than these two items. and thay are still avaliable somewhat cheep threw the National chains ( like Advance Auto )

But I'm not entirly sure how the story goes....