bio diesel , rubber parts list

[JFaughn]

I was woundering if any body had a list of parts to replace for hi % of bio , I know rubber fuel lines but not sure about the other parts that may come in contact with the fuel , like seals in pump ?

 

[HEMI®Dart]

I am interested in the answer too.

 

[bighornram]

Would DC allow bio in ANY percentage if it was harmful at all to the fuel system or any internal parts of the engine? I would think if it was going to cause a problem, the high percentage might just present it's problem faster than a lower one but ultimately the problem would show itself. Just a thought.

 

[67guzzler]

For the Dodge Cummins I don't know if anyone has gone to the trouble to analyze year by year what parts would be affected. If there are any injection pump parts that would be affected, it probably varies by model year & designs.



Maybe someone who has read posts from the past about bio & Dodge / Cummins will know more.



The general stuff that we all probably already know:



What I did find in researching this stuff this week (read -- burning up the search engines ), cars built before 1997 may have issues. But they're slow to develop and other than internal injection pump parts (what we all worry about!), are easy to fix.



Some comments I found:



"Degrades rubber parts on older vehicles. Vehicles manufactured before he mid-1990s might require upgrades of fuel lines (a cheap, easy upgrade), as biodiesel can eat through certain types of rubber. Almost all new vehicles should have no problem with biodiesel. "



and



"The switch to low-sulfur diesel fuel has caused most Original Engine Manufacturers (OEMs) to switch to components that are also suitable for use with biodiesel. Older diesel engines may use natural rubber parts which may need to be replaced with Viton A parts. Experience over the past seven years with B20 has found that no changes to gaskets or hoses have been necessary. "



and (not to be left out) the alarmist view:



"B100 is not compatible with some hoses and gaskets. B100 may soften and degrade certain types of rubber compounds found in hoses and gaskets (i. e. buna N, nitrile, natural rubber) and may cause them to leak and become degraded to the point they crumble and become useless. This could cause a fuel spill on a hot engine, could ruin a fuel pump, or could result in filter clogging as the hose material gradually wears away. If using B100, extreme care should be taken to ensure that any part of the fuel system that touches the fuel is compatible with B100. Some systems already have biodiesel resistant materials (i. e. Viton) but many do not because these materials are usually slightly more expensive. "



and from the National Biodiesel Board (and the one to believe, IMHO):



"The recent switch to low-sulfur diesel fuel has caused most Original Equipment Manufacturers (OEMs) to switch to components that are also suitable for use with biodiesel. In general, biodiesel used in pure form can soften and degrade certain types of elastomers and natural rubber compounds over time. Using high percent blends can impact fuel system components (primarily fuel hoses and fuel pump seals) that contain elastomer compounds incompatible with biodiesel, although the effect is lessened as the biodiesel blend level is decreased. Experience with B20 has found that no changes to gaskets or hoses are necessary. "



Some Links:



http://journeytoforever.org/biodiesel_vehicle.html#rubber



http://www.metaefficient.com/metaefficient/archives/biodiesel/



http://www.biodiesel.org/resources/fuelfactsheets/



So it seems that model year matters. Sorry that I don't know anything more specific. Hopefully someone else will!

 

[rbattelle]

The latest issue of TDR briefly mentions the effects of ULSD on some compounds. Among them it mentions nitrile rubbers as being susceptible to swelling.



My fuel system uses all Summit braided stainless -6AN hose made from nitrile rubber. A quick check of Aeroquip's website indicated all it's fuel hose is either nitrile or thermoplastic elastomer (they don't specify which thermoplastic elastomer they're using) - both of which are incompatible with benzene and toluene (listed as big parts of ULSD). Thermoplastic elastomer is rated "conditional" for xylene while nitrile is incompatible ("conditional" means you have to consult Eaton before using it).



Here's an interesting page on nitrile.



The only materials that appear to be fully compatible with all the chemicals in both biodiesel and ULSD are Viton and PTFE. PTFE is compatible with everything.



Just wondering what others think. Anyone considering replacing all their nitrile hose with PTFE or Viton? Sounds pricey.



-Ryan

 

[Mr. C]

This web page is from a marine perspective but the information is applicable for our use also.

 

[HEMI®Dart]

Running B100 for a month, I went to change the fuel filter ('94) and the square cut 0-ring (the one that goes on the center inlet) fell off the threaded stud into my hand. I usually have to Walk/Roll it on & off.

 

[Mr. C]

My fuel filter seals ('99) also swell but you don't re-use them any way so no problem.

 

[RNeuberger]

Rubber Parts

i have heard that after 1993 they stopped using rubber and began using viton, which holds up to even B100.

 

[SHobbs]

Over a year and a half and around 40k on B100 with out a single hickup. Truck runs smoother and is a little quieter than it was on #2. I do have a big line kit that is bio tolerant and as far as the fuel line from the tank to the filter it has held up so far. As long as I can get the B100 it will be in the tank.

 

[HEMI®Dart]

I noticed the molded rubber? hose from lift pump to pre-filter is wet w/ B100. It is sort of loose (spins easy) on the lift pump side. It has the constant tension OEM clamps on it. It's also 10 years old. I have run 1 tank of B100 only. Ordered a new one from Mopar.

 

[RNeuberger]

unless you have a diesel before 1993, my understanding is that on modifications are needed, because in 1993 they replaced rubber lines and seals with viton, which is compatible with biodiesel