Nasty Fuel System

[61sleepercab]

I had a friend cleaning a gasoline carburetor that had a green tinged goo that carb cleaner would not touch. A old mechanic said use DAWN dish washing soap and water to remove the dried up algae growing in the water and alcohol from unleaded gas. Go figure...... pond scum in a fuel system.

 

[Doug Roberts]

post some pictures

 

[Smokinyoda]

I recently picked up an AF truck with this same issue. Curious to know if anyone has run any biodiesel to try and clean this sludge out, heard it makes a great fuel system cleaner. I dont mind multiple filter changes, just want something i can pour in and burn that will clean out all the internal stuff I cant reach.

 

[red]

When it's gunk (for lack of a better term) bio diesel works as a great cleaner. When you're dealing with algae and bugs (what the picture looks like) bio diesel will compound the problem and turn it into a nightmare. Better to clean the tank by hand, clean or replace fuel lines/filters, run a few gallons with an additive such as 'biocide' to kill what is left, then biodiesel. Have a few spare fuel filters on standby.

The fuel system parts on these trucks are so easy to reach it's not worth skipping the small amount of manual labor to clean them. Plus it's a great time to upgrade to 'field serviceable' fuel lines if you're going to replace the lines anyways.

 

[goldneagle]

Anyone think of cleaning the tank out with a steam cleaner like they use to clean restaurant kitchens? I be the seam would get by the baffles .

 

[rustystud]

Anyone think of cleaning the tank out with a steam cleaner like they use to clean restaurant kitchens? I be the seam would get by the baffles .

We use the steam cleaner to clean our tanks all the time. Works great. Just be sure to get all the water out.

 

[jwesley74]

Hey guys I'm starting to overhaul the fuel system on my 87 m35a2 and drained and dropped the fuel system today and the tank is an absolute mess. It has a thick, sticky, tar-like residue on the inside of the tank (bio-diesel reside?). I took the fuel pump out the tank and it is covered in all that junk too.. I honestly don't know how the truck ran bc all the mesh wire intakes were completely clogged with this goo.... I'm taking apart the pump and cleaning it up best I can.. soaking everything in carb cleaner and what not...

I have two questions.... 1.) If the in tank fuel pump fails from all this junk... are any of you running the 24v Electric fuel pump kit to replace it? I really don't want to spend the extra $$$ to replace the in tank pump if that one is sufficient.

2) About this bio diesel residue... how do I go about cleaning it? Or is it even possible to clean? The local radiator shop said they can't clean it b/c of the baffles inside the tank... I'm honestly thinking about biting the bullet and getting a new tank to get rid of all that stuff and start over... I don't want contaminated filters and what not to be a constant problem...

Thanks for the input and advice in advanced!View attachment 509597

It's Algae... had same issue on our truck. Funny trick that cures it... drain your tank completely, pour 5 gallons of gasoline in your tank and let sit for a day or 2. Then drain. I did it twice and on 2nd time I agitated gas in the tank to make sure all the crud was out. I then sprayed using garden pump up sprayer, gas all around inside tank to further kill any algae. Once done, tank shined like new. Did same method to fuel filter canister and ran gas thru lines. I disconnected at primer pump. Gasoline kills and breaks down the algae. Once cleaned we now use Algae-X on every tank of fuel to avoid that issue again. Took about 5 filter changes to get all crud out of system and lines.