Biodiesel "flush"

[strelnik]

I often read that biodiesel cleans out all the residue in the tank, and this is why drivers switching to biodiesel need to clean out their secondary fuel filters more often and look at them at least once a week.

If this is true, then an ideal way to clean out a tank slowly, instead of sending it out for $200-400, would be to fill it with biodiesel COMPLETELY and let it sit for about a month, perhaps running 10-20 psi of compressed air into it after maybe a week, until the mix included a lot of sludge, then empty and refilter contents, do this a few times until the tank is pretty clean.

If the tank was already out and the holes plugged, neither air no light would get inside the tank and make the fuel go bad and you could do this several times until all the sludge in the tank was dissolved.

Anyone do this? Good idea? Bad idea? Crazy idea? The tank can always be grounded with a strap in case you are worried about static electricity.

Comments?

[fruitcakesa]

BD is a powerful solvent of petro based stuff among others and a long term B100 soak will likely dissolve most if not all the gunk.
I planned on running my homebrew BD in my cars soI pulled my tank and sloshed it out a few times with BD before simple green flushing till clean.
I didn't do a long soak but it couldn't hurt.
I also replaced all my fuel lines with viton and changed the filters including cleaning the intank strainer.
No fuel issues after 5k on BD other than some cold weather stumbling on a subzero day due to gelling which was my own faukt for not reducing my BD blend sooner.

[TMAllison]

You could just dump in a qt of a good biocide too.

[Jeremy5848]

Unless a diesel fuel tank has been sitting for a long time without being used, I do not understand why it should be full of crud of any kind. I switched all three of my diesels to biodiesel with almost no preparation and no significant problems. I ran two tanks of B20 as an "introduction" and then started using B100. (I did all the usual rubber hose changes, of course.)

Although I watched the primary filters in each car and changed them and the secondaries after a couple thousand miles, there was little crud in them, only a few black flakes. After awhile, and more out of curiosity than anything else, I pulled the tank screen from the '85 and found it almost completely clean. The other two cars have not had their screens cleaned during my ownership and I see no need at the present time.

Perhaps I am just lucky but I would think that the high miles and the variations of ownership (the '87 came from New York, the other two are west-coast cars) that I would have seen more crud than I did when I switched to biodiesel, based on some of the experiences related on this forum.

Jeremy

[TMAllison]

My expirience with my 85 is much like yours Jeremy. Burn some B20, hold your breath a bit and discover every is just fine.

I suspect the driving environment has more to do with dirty tanks than anything else. Driving lots of dirt roads or residing in parts of the country with high summer humidity, etc.

[lowriderdog37]

Just fill it up with B100 and carry an extra filter with you. I had to change mine once, and it's been fine since (3 B100 tanks later).