freightliner COLUMBIA CL112 Maintenance Manual page 113

Exhaust
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 and the top stack. 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 Columbia Workshop Manual for replace-
ment procedures.
2. Inspect the exhaust flex hose (see
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
1
06/01/93
1. Flex Hose
2. V-Band Coupling
3. Exhaust Pipe
Fig. 1, V-Band Coupling and Flex Hose
Columbia Maintenance Manual, January 2007
Fig. 1) for
Fig. 2.
2
3
4
f490024a
4. Turbocharger Exhaust
Outlet
4. If leakage exists, tighten the nut on the V-band
coupling 85 lbf·in (940 N·cm). If leakage persists,
install a new V-band coupling.
5. Inspect the turbo outlet pipe, and replace it as
needed.
6. Check the U-bolt clamps for tightness, and
tighten as needed.
7. Check the isolator at the base of the exhaust
stack elbow(s) (see
age, and dry rot. Replace as needed.
08/25/95
1. Exhaust Pipe
2. Exhaust Elbow Isolator
3. Mounting Nut
Fig. 2, Exhaust Elbow Isolator
8. Check for leakage at all wide-band exhaust
clamps. See Fig. 3.
If leakage exists, tighten the nuts 40 to 60 lbf·ft
(54 to 81 N·m). If leakage persists, inspect the
sealclamps. If necessary, install a new wide-band
exhaust clamp.
EPA07 Exhaust System
Inspecting
IMPORTANT: The Environmental Protection
Agency's 2007 regulations require lower ex-
haust emissions, thus requiring new exhaust
system components. See
the after-treatment device (ATD), which is part
of the after-treatment system (ATS), requires
special attention during regularly scheduled
49
Fig. 2), for cracking, dam-
1
2
3
f490127
Fig. 4. In particular
49/1