Which Seals Should be Replaced When Using Biodiesel in an Older Engine?

I would advocate Starting with small concentrations 2-5% of biodiesel. the crud is going to be flushed out of your fuel system, be prepared to change your fuels filters more often especially in the beginning. the 1st thing to change are any fuels lines, followed by seals & or o-rings on the fuel pump[s], anything after 03 will probably already have compatible rubber...

All my fuel lines are stainless steel?

Do I need different gaskets on the spin-on fuel filters too?

A few of our older GM diesels use a wick in the tank instead of the pickup tube, is any change needed?

Is any seal at the injector assy needs a change too?

Thanks

Here's a good resource:

http://www.biodiesel.org/#

Pg 48 0f this : http://www.nrel.gov/vehiclesandfuels/pdfs/43672.pdf has a material compatibility chart

I was refering the short flexible fuel lines usually right by the tank & motor. You won't have any trouble with spin on fuel filters. Just keep an eye on the injectors & fuel pumps, if the rubber parts show signs of swelling... You will have very few of these problems unless you are running high percentages of Bio. I'm assuming you are going to be using fuel that meets the specs. Homade fuel tends to have not been separated completely or finished as well as needed for problem free use.

I'd prefer an 80% during warm seasons and a 50% when cooler than 35°F to about -10°F

My point is don't be suprised if you have plugged filters & bursting hoses, if you sudenly start running your old high mileage diesel on 100% bio

Hello Garthh,

My old high mileage diesel loves 100% bio, even when mixed to about 70% bio / 30% SVO is marvelous. Use the correct hoses and pumps designed for the job and haven't been disappointed; go figure.

I used 3 filters rather rapidly but since have doubled the time between changing.

I started this thread not so much for my need of info as to clear the fog about the issue for others benefit. There is not really much to it, the expense to ensure optimal result is nominal.

Thanks for you time an valued input...

Oh I completely agree, most of the Bio horror stories I've heard revolve around crappy fuel or starting out with 100% & being surprised by plugged filters. The classic rich guy buys a diesel bug & the fuel pump craps from excess methanol, glycerin & caustic in his homade fuel to the tune $2500+ repair bill.

I'm out of the biz these days, but still remember a couple of things

Had a constantly improving process, but the business side needed some adjustments, that just couldn't be made