PREVOST X3-45 Multiplex, Maintenance Manual

Page: 104 / 1422

Section 04: EXHAUST SYSTEM
PA1562
2
1. EXHAUST AND AFTERTREATMENT
SYSTEM OVERVIEW
The technology behind clean emissions
technology is an exhaust
Aftertreatment
Device (ATD) which replaces today’s muffler.
The ATD primary function is to capture and
oxidize (regenerate) the particulate matter (soot)
in the engine exhaust gases. The ATD is split
into two main sections. The exhaust gases first
enter the
Diesel Oxidation Catalyst (DOC) and
then flow through the Diesel Particulate Filter
(DPF) ; together they capture and regenerate the
soot on a regular or passive basis. Through
constant monitoring of the exhaust gas
temperature and the system back pressure,
DDEC VI (Detroit Diesel) or EMS (Volvo) is able
to manage regeneration.
The ATD is rubber mounted to the vehicle
structure. This feature reduces the transmission
of vibrations to the ATD thus resulting in
extended life of ATD, brackets and also noise
reduction.
FIGURE 1: EXHAUST SYSTEM (DDC S60 SYSTEM
SHOWN, VOLVO D13 SIMILAR)
04017
1.1 MAINTENANCE
Inspect the exhaust system periodically for
restrictions and leaks. Figure 1 presents the
major components of the exhaust system.
Exhaust leaks are commonly the result of loose
clamp bolts, corroded or punctured pipes. In
addition to excessive noise, a leaking exhaust
system could allow toxic gases to enter the
vehicle. Damage to surrounding components
from hot gases could result as well. Replace
damaged or corroded exhaust components
immediately.
Inspect the exhaust system as follows:
•
At vehicle inspection intervals ;
•
Whenever a change is noticed in the sound
of the exhaust system ;
•
When components close to the exhaust
system get unnaturally dirty ; and
•
Whenever the exhaust system is damaged.
Replace damaged or corroded exhaust system
components without delay.
When operating the engine in a service garage or
in a closed area, the exhaust must be vented to
the outside. Place the shop vent hose over the
exhaust outlet pipe.
DANGER
Avoid breathing exhaust gases since they
contain carbon monoxide which is odorless and
colorless but harmful. Carbon monoxide is a
dangerous gas that can cause unconsciousness
and can be lethal. If, at any time you suspect
that exhaust fumes are entering the vehicle,
locate and correct the cause(s) as soon as
possible.
NOTE
The key to successful regeneration is high
exhaust temperature for an extended period of
time. For this reason, insulating blankets must
remain permanently on the exhaust system.
If insulating blankets are removed from the
system, the exhaust gases temperature may
not be high enough to permit efficient
particulate oxidation during passive
regeneration, resulting in increased fuel
consumption due to overuse of active or
stationary regeneration.