Fleet Maintenance - 10



The aftertreatment blues
As aftertreatment system issues continue to
plague fleets, relief may finally be in sight.

By David

@ DavidBrierleyFM

Ask the maintenance manager of any fleet
operating heavy duty diesel trucks what their
most common issue is, and you will likely
hear - without any hesitation - "aftertreatment systems." When U.S. regulations went
into effect starting with the 2007 model
year requiring diesel engines to emit lower
levels of nitrogen oxide (NOx) and particulate matter into the atmosphere, OEMs had to
meet those new requirements. As with most
new technologies, aftertreatment systems had
various bugs and issues from the start.
Compounding the problem was the fact that
fleets had no experience with these complex
exhaust treatment systems, so the only knowledge they had regarding how to service and
maintain them was what the OEMs provided,
not real-world trial and error. Fleets that had
not yet experienced the new aftertreatment
systems delayed replacing their older trucks
as long as possible after hearing of troubles
from other fleets, but most eventually had to
concede and purchase vehicles equipped with
these systems.
OEMs have made drastic improvements
to aftertreatment systems over the years,
but regulations have also tightened further,
requiring additional components and making
the systems even more efficient, but also
more complex. Phase 1 emissions standards
impacted trucks starting with the 2014
model year, and fleets are still seeing repercussions from those regulations today since
many operate vehicles up to five years before
replacing them.

Aftertreatment system

Some fleets today estimate that up to 50
percent of their downtime is due to aftertreatment system issues, though they say there is
a downward trend in aftertreatment-related downtime as they replace their trucks
with model year 2019 and newer vehicles.
It seems that OEMs have been able to tweak
and improve the systems, resolving common
issues as they are discovered.
It also helps that fleets have had time to
learn the ins and outs of these systems and
the best ways to maintain them in order to
prevent unscheduled downtime. One common
trend among fleets in keeping aftertreatment
systems in good health is diesel particulate
filter (DPF) regenerations (regens).
Fleets are training their drivers to always
allow trucks to run regens when the vehicle's

10 Fleet Maintenance | October 2020

		┬╗Some fleets
today estimate
that up to 50
percent of their
downtime is due
to aftertreatment
system issues.
157625650 | Vitpho
| Dreamstime

systems require it, since ignoring the warning light often leads to more trouble down
the road. They are also frequently running
forced regens using OEM or aftermarket diagnostic tools. Some fleets will run forced regens
on trucks whenever they are parked in the
yard. This preventive maintenance can help
prevent aftertreatment issues later on.
Another way fleets avoid aftertreatment
issues is by monitoring and limiting idle
time. Idling a diesel engine can clog the DPF
since it is not running hot enough to perform
a regen. Using auxiliary power units (APUs) or
bunk heaters can help mitigate this issue by
reducing the amount of time the truck idles,
especially during periods of cold or hot weather when cabin climate control is necessary.
Fleets also cite technician training as
imperative in keeping aftertreatment systems
operating smoothly. Engine manufacturers
are able to train fleet technicians on the latest
technologies, ensuring they have the latest
knowledge and expertise on aftertreatment
systems. This is especially important considering Phase 2 emissions standards will impact
2021 and newer model year trucks.

Alternative fuel

As emissions regulations have become more
and more strict, OEMs have made necessary
changes to engine aftertreatment systems to
meet the requirements. But many have also
begun to develop engines powered by alternative fuels that require simpler aftertreatment
or no aftertreatment systems at all.
The solution that has received the most
attention has been battery electric vehicles
(BEVs). BEVs have been making their way into
the passenger car segment, and we are just
starting to see the very first electric trucks
make their way to the market as well. While
BEVs have zero tailpipe emissions with no

aftertreatment system at all, there are several hurdles to overcome before this solution is
ready for the masses. For one, the U.S. power
grid and charging infrastructure is nowhere
near ready to charge BEVs for every fleet
(not to mention consumer vehicle charging).
Plus, battery technology has not yet reached
the tipping point where batteries can both
provide enough range and be lightweight
enough to be usable for long haul truck routes.
Other alternatives, including propane
autogas and hydrogen fuel cell vehicles,
can also produce zero or near-zero tailpipe
emissions with little or no aftertreatment
systems. Hydrogen fuel cell technology is
still in its infancy, but concept trucks from
manufacturers such as Kenworth, Nikola,
Hyundai, Mercedes-Benz, Daimler, and Hino
show it could be a promising solution in the
future for fleets looking to move away from
traditional diesel trucks and their aftertreatment systems.
Propane autogas vehicles are on the market
today and have been slowly gaining popularity. While they are mainly seen in the light and
medium duty commercial vehicle segments,
propane autogas vehicles require much less
complex aftertreatment systems to meet and
exceed government regulations, meaning less
maintenance and downtime.
"Propane's low-carbon chemical properties
allow it to power an engine while reducing the
emissions released into the atmosphere," says
Todd Mouw, president of ROUSH CleanTech.
"Engines fueled by propane autogas ... do not
need additional emission fluids or extra valve
adjustments." (Read more on pg. 54).
There is no one-size-fits-all solution for
every fleet when it comes to solving the aftertreatment system problem. Alternative fuel
vehicles may be a solution for many fleets
in the future, but for now, the updates and
improvements OEMs are continually making
to diesel engines will help reduce downtime,
both scheduled and unscheduled.

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Fleet Maintenance

Table of Contents for the Digital Edition of Fleet Maintenance

Uptime: How Fleets Can Connect with Tech Schools
Editor's Note: The Aftertreatment Blues
Keys to Maximizing Trailer ROI
Best Practices for Maintaining Hydraulic Braking Systems
Solving the Parts Puzzle
Contending with Accelerated BEV Tire Wear
Cold Weather HVAC Considerations
Management: CMMS Marketplace
Economic Outlook: Signs of Economic Recovery
Diagnostics: Choosing the Right Diagnostic Tool for Roadside Triage
Fleet Parts & Components
Tools & Equipment
Guest Editorial: The Propane-Powered Alternative
Fleet Maintenance - 1
Fleet Maintenance - 2
Fleet Maintenance - 3
Fleet Maintenance - 4
Fleet Maintenance - 5
Fleet Maintenance - 6
Fleet Maintenance - 7
Fleet Maintenance - Uptime: How Fleets Can Connect with Tech Schools
Fleet Maintenance - 9
Fleet Maintenance - Editor's Note: The Aftertreatment Blues
Fleet Maintenance - 11
Fleet Maintenance - Keys to Maximizing Trailer ROI
Fleet Maintenance - 13
Fleet Maintenance - 14
Fleet Maintenance - 15
Fleet Maintenance - 16
Fleet Maintenance - 17
Fleet Maintenance - 18
Fleet Maintenance - 19
Fleet Maintenance - Best Practices for Maintaining Hydraulic Braking Systems
Fleet Maintenance - 21
Fleet Maintenance - 22
Fleet Maintenance - 23
Fleet Maintenance - 24
Fleet Maintenance - 25
Fleet Maintenance - Solving the Parts Puzzle
Fleet Maintenance - 27
Fleet Maintenance - 28
Fleet Maintenance - 29
Fleet Maintenance - 30
Fleet Maintenance - 31
Fleet Maintenance - Contending with Accelerated BEV Tire Wear
Fleet Maintenance - 33
Fleet Maintenance - Cold Weather HVAC Considerations
Fleet Maintenance - 35
Fleet Maintenance - Management: CMMS Marketplace
Fleet Maintenance - 37
Fleet Maintenance - 38
Fleet Maintenance - 39
Fleet Maintenance - Economic Outlook: Signs of Economic Recovery
Fleet Maintenance - 41
Fleet Maintenance - Diagnostics: Choosing the Right Diagnostic Tool for Roadside Triage
Fleet Maintenance - 43
Fleet Maintenance - 44
Fleet Maintenance - 45
Fleet Maintenance - Fleet Parts & Components
Fleet Maintenance - 47
Fleet Maintenance - 48
Fleet Maintenance - 49
Fleet Maintenance - 50
Fleet Maintenance - Tools & Equipment
Fleet Maintenance - Classifieds
Fleet Maintenance - 53
Fleet Maintenance - Guest Editorial: The Propane-Powered Alternative
Fleet Maintenance - 55
Fleet Maintenance - 56
Fleet Maintenance - A1
Fleet Maintenance - A2
Fleet Maintenance - A3
Fleet Maintenance - A4