I've been running an 83 F250 on B100 for over a year with periodic trouble of fuel filters clogging, running out of fuel and getting air in the lines from faulty hoses. The truck (*****) has been running like a champ (I'm rebuilding the brake system on Saturday).
History: the truck konked out three times in a row on a trip around Fortuna, CA. A good local mechanic helped me out by logically going through the fuel delivery system and selling me parts (though I really didn't need the switch that is such a pain to change out) while letting me do the labor in his yard. The clogged or leaking fuel line persisted as a mystery, so to get me down the road we bypassed the steel line along the body to the prefilter/water trap from the switch to the fuel pump that lifts to the filter. (btw, symptoms of the truck were: long hard smokey starts, flowed by konking out on the highway just like running out of gas or getting air in the lines, then later being able to start, drive a while, then konk out again, even after replacing the fuel pump)
When we got home I bought some length of 3/8 rubber fuel hose for the delivery and 5/16 tefflon lined transmission hose for the return at Kragan, I reassembled the prefilter and removed the steel lines. A few months latter the 2 nd or 3rd prefilter clogged so bad I lost power on the freeway and blew loads or blue/white smoke as I limped home (stupid me for pushing the truck so hard to get ten miles before getting to Home Depot to fix it). Well, I replaced the filter and the spongy rubber fuel delivery line (the return line is good) and the truck is running pretty good. I replaced it with clear, reinforced vinyl tubing. For the passed week I've been watching air bubbles (mostly tiny) bubble up my fuel system and I regularly have to bleed the air (each time I stop).
The vinyl tubing seems to be bleeding air in where it is reinforced (I'm not sure though) between the Fram G-3 prefilter and the water trap. From the water trap to the pump is hose that seems to be good that I think I got from Poncie's (the mechanic, the vinyl tubing replaced the rubber I had got at Kragans).
So I have a few questions: does any body have any thoughts on the true cause of the problems, what's the best fuel line to use with B100, and what's the problem with getting air in the engine?
Trouble shooting is a lost art but well try.
First off who is supplying the bio and at what quality?
2nd...New fuel line from any store is capable of handling bio or diesel as long as its fuel
3rd..Its a concern that you mentioned so much trash in your filters. Correctly produced bio should have been filtered down to 1 micron absolute prior to pumping into your tank. This may be a dumb question but by chance are you running veggy oil not biodiesel?
I buy the bio at Biofuel Oasis in Berkeley, CA. They make it from waste potato chip oil to ASTM standards. I fell pretty confident about their product. Pretty widely used here. It's definatelty biodiesel!
I replaced the plastic Fram G-3 prefilter with a steel housed Fram G-15. No bubbles now. I'll follow up if they do recur.
The previous owner ran bio from the same soure. Some one bypassed the water separator and put the G-3 in. I have kept using the same G-3 prefilter, but put the water separator back in line. After doing that I put in the nylon tubing and could see the bubbles in the tubing after the G-3. Could that prefilter have been the problem the whole time? I'll let you know how the G-15 works out.