august2021 - 28

SPOTLIGHT ON DRIVETRAIN
» Shown here is a stage 1 fuel filter/water separator
common to on-highway truck applications.
Photo courtesy of Cummins Filtration
F
uel contaminants, and sub-par fuel in general,
can cause problems for fleets. The good news is
that a few simple steps can be taken to help avoid
many issues.
" Impurities in a fuel system will reduce engine
power and fuel efficiency and cause uneven
engine performance, " said Phil Cary, southeast
regional fleet service manager for Mack Trucks,
a manufacturer of heavy-duty trucks, engines,
and transmissions. " Chemical or dirt debris can
also cause significant damage to all fuel-carrying
components, from the fuel tank to the injectors. "
" Diesel fuel impurities can also lead to fuel
system deposit formation, plugged fuel filters,
and the growth of microbes in the fuel, " said
Eric Trimble, product manager at Lubrication
Specialties Inc. (LSI), maker of Hot Shot's Secret
fuel and oil additives. " Impurities can also lower
a fuel's lubricity properties. "
" Water in the system can cause frozen or gelled
fuel in filters and lines, which results in reduced
power or even the engine shutting down, " said
Clay Parks, vice president of development at
Rislone, a maker of additives and treatments for
fuel, engine oil, and transmission fluid.
All of these issues can financially impact a
fleet in various ways. Mechanical failures require
expensive part replacements, not to mention the
cost of extensive downtime. " Consistent water
contamination and microbial growth in bulk
tanks can lead to additional treatment costs, like
a biocide or water dispersant, " Trimble added.
In addition to water and microorganisms, Cary
pointed out that diesel fuel can contain other
contaminants including wax in cold weather,
hard particles, debris, and other sediments. Diesel
exhaust fluid (DEF), accidentally added to the fuel
tank instead of the DEF tank, is another source of
contamination that happens all too often.
Warning signs to watch for
There are steps a fleet can take to help prevent
fuel issues from turning into fuel system issues.
" I always stress the importance of solid drivKeys
to efficient fuel
system performance
Preventive maintenance tips to help fleets
identify and resolve fuel-related issues before
a mere reduction in engine performance
leads to a major mechanical issue.
by Gregg Wartgow
28 Fleet Maintenance | August 2021
er-technician feedback to help identify intermittent
issues, " said Nick Rivera, a commercial
vehicle lubricants application engineer with
ExxonMobil Fuels and Lubricants. " With any
potential fuel-related issue, I would first ask
the driver if he or she has detected a significant
loss of performance. A driver would likely notice
some kind of derated engine output such as
stumbling, erratic idle, poor acceleration, excess
smoking, and even more frequent aftertreatment
regen sets. "
Aside from gathering driver feedback, technicians
have other steps they can take to identify
fuel-related issues.
" Performing a simple visual check of the fuel
separator is important, " Rivera said. " Is there
excess sludging? Is water showing up periodically?
Another thing to look at is if there are any signs of
august2021

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