Fleet Maintenance - 54

ยป The process for diagnosing brake
systems on electric vehicles will require
the increased use of diagnostic software
to determine system issues.
Image courtesy of Bendix

How will EVs impact
commercial truck
braking systems?
Electrified truck systems will trigger changes
to fleet maintenance operations.
All signs indicate that in a few short years,
initial production of large electric commercial
vehicles will be a reality in North America.
Original equipment manufacturers, teaming
with partners like Bendix, are developing the
architecture for these vehicles with an expected rollout by 2021 or 2022. As the industry
speeds its drive toward increased electrification, fleets soon will be able to order heavy duty
electric vehicles in quantity.
Engineers are working out platform details,
but enough key pieces are in place to gain a
big-picture understanding of what those
changes will look like. Some vehicle parts will
become easier to maintain because electrifi-

By Kevin Romanchok

cation will give them the ability to diagnose
themselves. Technology will be added, carrying
with it new challenges.
Electric vehicles will also impact a heavy
duty truck's braking components. Let's take a
high-level look at how electrification will likely affect the maintenance of air management,
brake control, and wheel-end systems.

Air management

In the absence of a diesel engine, components
and accessories that rely on that engine for
power will become electrically driven.
The compressor is among these components.

Bendix Commercial Vehicle Systems, a member of the Knorr-Bremse Group, develops and supplies leadingedge active safety technologies, energy management solutions, and air brake charging and control systems
and components under the Bendix brand name for medium and heavy duty trucks, tractors, trailers, buses,
and other commercial vehicles throughout North America. Romanchok is the director, eMobility / new business
development for Bendix Commercial Vehicle Systems LLC. In his almost 20 years at Bendix, Romanchok has led
the Electronics and Actuation business units, driving the release and growth of multiple products, from stability to
data management systems. As director of the company's eMobility initiative, he now leads product and customer
strategies, along with new business development and M&A efforts.

54 Fleet Maintenance | October 2019

Driving the compressor electrically means
adding a motor to the brake system. That motor
may be 48V, but it will more likely be higher
voltage, from 400V to 1,000V. High-voltage
systems involve unique maintenance practices and typically require specialized training.
Technicians will also need to be aware of a
new, separate filter for the compressor, which
no longer can utilize the engine oil and air filter
as part of its filtering process. Today, compressors are cooled with lubrication that is shared
with the engine. Electrically driven compressors will require a new cooling method - possibly through liquid cooling. This adds another
maintenance factor that doesn't currently exist.
Rather than separate motors, a single electric motor may end up driving engine-mounted
accessories such as the air conditioning and
power steering, in addition to the air compressor. Technicians must become familiar with
whatever configuration is chosen.
The air dryer is the next step in the system.
In an electric vehicle, the air dryer will use
a solenoid or electronic control unit (ECU)
to control the system when it is purging. As
a smart component, it will add a monitoring
element that assesses the health of the system
- such as communicating cartridge life and air
system leakage. These advantages may make
maintenance easier than it is today.
The same can be said of the air governor,
which determines when a compressor builds
air pressure. Functioning as part of an electric
vehicle, an intelligent air governor will contribute added features and prognostic capabilities
to the air brake system - potentially assisting
maintenance efforts.

Brake control

The probability is high that electronic braking
systems (EBS) will emerge as the base brake
control system. If not EBS, then the addition of
electronically controlled brake valves may be
added to the current anti-lock braking system
(ABS). While EBS has been in production for
20 years in Europe, ABS is still prevalent for
North American vehicles.
Now, the combination of automated driving
and electrification is causing the industry to
reconsider ABS versus EBS. ABS is an intervention system which electronically activates only
periodically to limit locking of the wheels when
braking, limits wheel spin-up with traction
control, and provides individual wheel braking
to maintain vehicle stability. EBS controls the
braking pressure electronically on every stop.
Today's brake control uses pneumatic valves
with solenoids. In EBS-based electric vehicles,
valves that have ECUs will be mounted on
the pneumatic valves, requiring technicians
to make greater use of diagnostic software to
service the brake control. These valves may
include electronic park brake valves.


Fleet Maintenance

Table of Contents for the Digital Edition of Fleet Maintenance

Uptime: Are all systems secure?
Cover Story: Connecting to the future
Vehicles: Engine trends impacting performance and fuel efficiency
In the Bay: Understanding tire pressure monitoring and management systems
Shop Operations: How fleets can benefit from RCM
Management: Are you a good global citizen?
Economic Outlook: WDTKAWDTKI?
Powertrain: What are fault code action plans, and how can they help improve the vehicle diagnostic process?
Braking & Collision Avoidance: How will electric vehicles impact commercial truck braking systems?
Fleet Parts & Components
Tools & Equipment
Guest Editorial: Differences servicing air disc brakes versus drum brakes
Fleet Maintenance - 1
Fleet Maintenance - 2
Fleet Maintenance - 3
Fleet Maintenance - 4
Fleet Maintenance - 5
Fleet Maintenance - 6
Fleet Maintenance - 7
Fleet Maintenance - Uptime: Are all systems secure?
Fleet Maintenance - 9
Fleet Maintenance - Cover Story: Connecting to the future
Fleet Maintenance - 11
Fleet Maintenance - 12
Fleet Maintenance - 13
Fleet Maintenance - 14
Fleet Maintenance - 15
Fleet Maintenance - 16
Fleet Maintenance - 17
Fleet Maintenance - 18
Fleet Maintenance - 19
Fleet Maintenance - Vehicles: Engine trends impacting performance and fuel efficiency
Fleet Maintenance - 21
Fleet Maintenance - 22
Fleet Maintenance - 23
Fleet Maintenance - 24
Fleet Maintenance - 25
Fleet Maintenance - 26
Fleet Maintenance - 27
Fleet Maintenance - 28
Fleet Maintenance - 29
Fleet Maintenance - 30
Fleet Maintenance - 31
Fleet Maintenance - 32
Fleet Maintenance - 33
Fleet Maintenance - In the Bay: Understanding tire pressure monitoring and management systems
Fleet Maintenance - 35
Fleet Maintenance - 36
Fleet Maintenance - 37
Fleet Maintenance - 38
Fleet Maintenance - 39
Fleet Maintenance - 40
Fleet Maintenance - 41
Fleet Maintenance - 42
Fleet Maintenance - 43
Fleet Maintenance - Shop Operations: How fleets can benefit from RCM
Fleet Maintenance - 45
Fleet Maintenance - 46
Fleet Maintenance - 47
Fleet Maintenance - 48
Fleet Maintenance - 49
Fleet Maintenance - Management: Are you a good global citizen?
Fleet Maintenance - Economic Outlook: WDTKAWDTKI?
Fleet Maintenance - Powertrain: What are fault code action plans, and how can they help improve the vehicle diagnostic process?
Fleet Maintenance - 53
Fleet Maintenance - Braking & Collision Avoidance: How will electric vehicles impact commercial truck braking systems?
Fleet Maintenance - 55
Fleet Maintenance - Fleet Parts & Components
Fleet Maintenance - 57
Fleet Maintenance - 58
Fleet Maintenance - 59
Fleet Maintenance - 60
Fleet Maintenance - 61
Fleet Maintenance - Tools & Equipment
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Fleet Maintenance - Classifieds
Fleet Maintenance - Guest Editorial: Differences servicing air disc brakes versus drum brakes
Fleet Maintenance - 75
Fleet Maintenance - 76
Fleet Maintenance - I1
Fleet Maintenance - I2
Fleet Maintenance - S1
Fleet Maintenance - S2
Fleet Maintenance - S3
Fleet Maintenance - S4
Fleet Maintenance - S5
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Fleet Maintenance - S20