freightliner Argosy COE - 49-01 Exhaust System Inspection (Noise Emission Control)

49–01 Exhaust System
Inspection (Noise
Emission Control)
In addition to inspecting the exhaust system at the
scheduled maintenance interval, inspect the exhaust
system if the noise level of the vehicle has in-
creased. Replace parts that show leakage, wear, or
damage, with genuine Freightliner parts.
Pre-EPA07 Exhaust System
Inspecting
1. On all vehicles, check the condition of the muffler
body, the top stack, and the heat shield. See
Fig. 1. Check the inlet/outlet tubes for leakage,
dents, and corrosion, and check for holes in the
muffler. Replace parts as required. Use new
parts, equivalent to parts originally installed on
the vehicle. See Group 49 of the
Century Class
Trucks Workshop Manual
for replacement
procedures.
2. Inspect the exhaust flex hose (see Fig. 2) for
leakage, wear, or damage. Replace with new
parts if replacement is needed.
3. Check for leakage at the V-band coupling, which
attaches the exhaust pipe to the turbocharger
exhaust outlet. See Fig. 2.
If leakage exists, tighten the nut on the V-band
coupling 10 lbf·ft (14 N·m). If leakage persists,
install a new V-band coupling.
4. Inspect the turbo outlet pipe, and replace it as
needed.
5. Check the U-bolt clamps for tightness, and
tighten as needed.
6. Check the isolator at the base of the exhaust
stack elbow(s) (see Fig. 3), for cracking, dam-
age, and dry rot. Replace as needed.
7. Check for leakage at all wide-band exhaust
clamps. See Fig. 4, Fig. 5,orFig. 6.
If leakage exists, tighten the nuts 40 to 60 lbf·ft
(54 to 81 N·m). If leakage persists, install a new
wide-band exhaust clamp. Do not re-use
Sealclamps.
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. 7. 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.
01/06/99
1
2
2
3
3
f490170
1. Exhaust Clamp
2. Lower Heat Shield Fastener
3. Upper Heat Shield Fastener
Fig. 1, Vertical Exhaust Stack and Heat Shield
Exhaust 49
Century Class Trucks Maintenance Manual, January 2007 49/1