What to use to clean out old diesel fuel lines?

Is there anything a person can use to clean out the fuel lines from the fuel tank to filters and to the injection pump? The tractor
has been sitting a few years and had biodiesel in it. Will be replacing the fuel tank.

carb cleaner, and air

I use brake clean and then dry with compressed air.

I use E85 let it se over night works like a dream.

I actually use E-85 as a parts cleaner. I have a little bowl and a brush. Works very well.

For dried up and varnish-like fuel, E85, brake clean, and carb cleaner work. But you mentioned biodiesel:

Do you have an issue with the bacteria, or 'Diesel Bug' sliming up your lines? I had read on this forum and others about the bacteria that can live and propagate in low-sulphur diesel (especially biodiesel) and gum up a fuel system. I never really paid much attention to it nor even believed it was that big of an issue: I figured that not many self-respecting bacteria would live in diesel fuel.

I learned my lesson: I went to get one of my old Masseys ready to sell. It had been sitting for just under two years. The tank had fresh diesel with stabilizer in it before I parked it, stored in a dry shed.

Holy smackers - what a nightmare. The diesel bacteria problem had got me bad: Every fuel system component was full of some thick, green, tar-like, slimy sludge. It looked like something you'd find rotting in Ted Nugent's shower drain. It was a struggle to clean, and I spent a long time trying to find something that would dissolve it, but with little luck. Brake clean wouldn't touch it. The best solution was to let things soak in methyl hydrate, but even it wasn't superb. Once clean, I ran fresh diesel through it with a healthy dose of 'Biobor JF' to kill any remaining bacteria so the bacteria couldn't propagate/multiply. It was a nasty, sticky, slimy job, and I've learned my lesson not to keep diesel sitting around for too long.

IF the water is not allowed to build up on tanks The bactieria can't live on the fuel it is the water line they live at. We drain check our tanks each year or two for any water that has made it to the bottom of the tanks with a drain plug in the bottom. We put them in if they don't have one. My local fuel distributor was sayinf that you need to put something like a tablespoon of the biocide stuff on the engine oil if you have had a problem in a piece of equipment somehow it gets into the oil and will recontaminate the fuel again. didn't just follow that thinking but that is what he was told by someone that had a recurring problem with it I guess.

The one I did used spray B12 and piece of tye wire. Got so B12 would go thru and let fuel get rest out.

For some manual labor you can use a liner from a mig welder as a snake to rod out the hard stuff.

Do Not use biodiesel in a tractor that is going to sit for any period of time.... Only use biodiesel if you will use it now and use it all up...

I had a Massey 44 Diesel that had sat for a few years and all the lines were plugged. A friend and I were working on it and we could not find anything that would really work. Friend came out of the shop with a can of zip strip paint remover. Tried that and in no time we had all the lines clean and tractor running.
DWF