ULSD and Leaks
Read this on another site and thought you all my want to read this PDF from Chevron: http://www.chevron.com/products/prod...tb_2005Aug.pdf
A while back, I sent requested some info on this from Cummins Customer service. Here is the response I got:
In October of 1993 a switch to low sulfur diesel fuel was required by
the EPA. A color coding of fuels was driven by IRS regulations published
in Nov, 1993 and the EPA in Oct, 1993. The EPA instituted a blue dyed
fuel to distinguish the high sulfur fuel. There was also a red dyed
fuel available for the low sulfur tax exempt fuel. It is our understanding
that the color-coding is no longer required, however, some of the dyed
fuel may still be around.
Cummins engines will perform satisfactorily on low sulfur fuels,
however, engines that have been running on high sulfur fuels then switched to
low sulfur fuels may have fuel pump seal leaks. This is caused by the
difference in the 'swell rate' of seals exposed to the different amounts
of sulfur. Seals tend to swell more with high sulfur fuel and less with
low sulfur fuels. The Cummins PT fuel pumps had most of the fuel leaks
at that time but Cummins no longer uses the PT fuel system on highway
engines.
We expect the low sulfur fuel transition to be transparent to
customers. The 15 ppm S fuel will meet Cummins fuel requirements with the only
difference being sulfur content. Customers will not lose warranty or
suffer any reduced life, due to the switch. The only perceivable
concern is some possible seal leakage due to extremely low aromatic content
as a side effect to sulfur removal, compared to higher sulfur fuels. We
expect that risk will be minimal at this point because most low sulfur
fuel retains sufficient aromatic content and Cummins fuel system seals
have been improved to tolerate that.
In October of 1993 a switch to low sulfur diesel fuel was required by
the EPA. A color coding of fuels was driven by IRS regulations published
in Nov, 1993 and the EPA in Oct, 1993. The EPA instituted a blue dyed
fuel to distinguish the high sulfur fuel. There was also a red dyed
fuel available for the low sulfur tax exempt fuel. It is our understanding
that the color-coding is no longer required, however, some of the dyed
fuel may still be around.
Cummins engines will perform satisfactorily on low sulfur fuels,
however, engines that have been running on high sulfur fuels then switched to
low sulfur fuels may have fuel pump seal leaks. This is caused by the
difference in the 'swell rate' of seals exposed to the different amounts
of sulfur. Seals tend to swell more with high sulfur fuel and less with
low sulfur fuels. The Cummins PT fuel pumps had most of the fuel leaks
at that time but Cummins no longer uses the PT fuel system on highway
engines.
We expect the low sulfur fuel transition to be transparent to
customers. The 15 ppm S fuel will meet Cummins fuel requirements with the only
difference being sulfur content. Customers will not lose warranty or
suffer any reduced life, due to the switch. The only perceivable
concern is some possible seal leakage due to extremely low aromatic content
as a side effect to sulfur removal, compared to higher sulfur fuels. We
expect that risk will be minimal at this point because most low sulfur
fuel retains sufficient aromatic content and Cummins fuel system seals
have been improved to tolerate that.
With this info from Chevron I now know why when I filled up today the darn hose was dripping fuel. With this info you now know that it's not only Chevron Diesel that will cause this problem [:@]



