Sterling Trucks Acterra MX - Manual (Page 125)

49–01 Exhaust System
Inspecting (Noise
Emission Controls)
NOTE: In addition to the maintenance interval in
this manual, inspect the exhaust system if the
vehicle has a noticeable increase in noise level
at any time. Replace parts that show leakage,
wear, or damage.
Pre-EPA07 Exhaust System
Inspecting
1. Check the muffler body, muffler outlet stack, muf-
fler shield, and inlet tubes, for leakage, dents,
corrosion, or holes in the muffler.
2. Inspect the exhaust pipe for leakage, wear, or
damage; replace with new parts, if needed. Do
not reuse wide-band clamps. Once a clamp is
removed, it must be replaced.
2.1 On Caterpillar and Cummins engines,
check for leakage at the V-type clamp
that attaches the exhaust pipe to the tur-
bocharger exhaust outlet. If leakage ex-
ists, tighten the nut on the V-type clamp
85 lbf·in (940 N·cm). If leakage persists,
install a new V-band coupling.
2.2 On Mercedes-Benz MBE900 engines,
check the tightness of the fasteners that
attach the exhaust pipe to the exhaust
flange (see
Fig. 1 ). If needed, tighten the
fasteners 33 lbf·ft (45 N·m) for Mercedes-
Benz MBE900 engines.
3. Check for leakage at each wide-band exhaust
clamp (see
Fig. 2 ). If leakage exists, tighten the
nuts 40 to 60 lbf·ft (54 to 81 N·m). If leakage per-
sists, install a new wide-band exhaust clamp.
See Group 49 of the
Acterra ® Workshop Manual
for instructions.
EPA07 Exhaust System
Inspecting
IMPORTANT: The Environmental Protection
Agency’s 2007 regulations require lower ex-
haust emissions, thus requiring new exhaust
system components. See
Fig. 3 . In particular
the after-treatment device (ATD), which is part
of the after-treatment system (ATS), requires
special attention during regularly scheduled
maintenance inspections. If any discrepancies
are discovered, refer to the engine manufactur-
er’s service literature for repair instructions.
Definitions of ATS Components
Refer to the following list of definitions of ATS com-
ponents.
•
After-Treatment System (ATS)—the entire ex-
haust system from the turbocharger to the ex-
haust stack or tail pipe.
•
After-Treatment Device (ATD)—a muffler-like
canister that houses a DPF, DOC, and sensors.
f490032a 10/05/94
A
A. Check the Tightness of These Fasteners
Fig. 1, Typical Exhaust-Pipe to Exhaust-Flange
Fasteners
f490005a 10/05/94
Fig. 2, Wide-Band Exhaust Clamp
Exhaust
49
Acterra Maintenance Manual, January 2007 49/1