Fleet Maintenance - 25

Changes in maintenance

Of the differences between drum brakes and
ADBs, the most notable are those related to maintenance and servicing.
"Fleets should expect simplified maintenance
schedules," says Savvas Constantinides, senior
commercial product manager, Haldex. "Air disc
brakes have different maintenance procedures,
but [the procedures] are simpler and [are] required
less often [than with drum
brakes]." Haldex is a developer and supplier of brake and
suspension solutions in the
commercial vehicle industry, as
well as a developer of technologies for electric and autonomous vehicles.
On the ADB side, there are
longer pad replacement and
longer rotor replacement
intervals when compared to
the drum shoe and the drum
itself for drum brake systems.
Not only is the friction material replacement interval longer
with ADBs, but the maintenance required to change
the friction material is also
much quicker and simpler.
Manufacturers have simplified
the replacement process so that
a technician need only swap
a new pad in place of the old
pad within a mounted bracket. It is always recommended to
carry out a thorough inspection
when replacing brake pads. A
drum and shoe system is more
labor-intensive, as technicians
must work on a bigger, bulkier,
and heavier system than ADBs.
"Service times [with ADBs]
compared to drum brakes are
significantly less," Ryan says.
"With the vehicle jacked up and
the wheels off, a pad change
and a few prudent inspection
checks will take only a few
minutes per wheel end."
"The ADBs friction will last
longer; and if there is a chance
that you have to replace the
pads before you trade the vehicle out, the replacement and
labor time to do that is much
less - around one quarter of
the time you would spend on
replacing drum brake friction," says Bendix Spicer's
McComsey. "It's that kind of
difference that is a real key
benefit from a service perspective for the fleet for reducing
their overall maintenance and
labor costs."
Along with longer pad life,
the rotor in the ADB system
has a longer service life than
its comparative counterpart,
the drum. With drum brake

systems, it is not uncommon for the drum to be
replaced at the time of friction material change.
With ADB systems, McComsey says that the rotor
should last two to three pad changes, further
saving fleets in costs associated with parts, labor,
and downtime.
Another significant difference in brake maintenance is that the servicing of slack adjusters,
S-cam bushing wear checks or shaft greasing, free

stroke checks, and other maintenance procedures
are all eliminated when servicing ADBs compared
to drum brakes.
"While the perception may be that air disc
brakes are maintenance-free, the reality is that,
like any other braking system, a regularly planned
maintenance schedule is integral to maximizing
performance, enhancing safety, and achieving optimal life," says Jeff Wittlinger, business

Hendrickson

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©2019 Hendrickson USA, L.L.C. All Rights Reserved. All trademarks shown are owned by Hendrickson USA, L.L.C., or one of its affiliates, in one or more countries, except for MAXX22T, which is owned by WABCO.

August 2019 | VehicleServicePros.com

http://www.MAXX22T.com http://www.VehicleServicePros.com/10121758

Fleet Maintenance

Table of Contents for the Digital Edition of Fleet Maintenance