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.
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.
On Caterpillar and Cummins engines, check for
leakage at the V-type clamp that attaches the
exhaust pipe to the turbocharger exhaust outlet.
If leakage exists, tighten the nut on the V-type
clamp 50 lbf·in (560 N·cm). Using a plastic ham-
mer, tap around the clamp, then tighten again to
50 lbf·in (560 N·cm). If leakage persists, replace
the clamp.
3.
Check for leakage at each wide-band exhaust
clamp. See
. If leakage exists, tighten the
nuts on Torca "Torctite" exhaust clamps 40 to 60
lbf·ft (54 to 81 N·m). If leakage persists, install a
new wide-band exhaust clamp. See Section
49.00 of the
School Bus Chassis Workshop
Manual
for procedures.
f490005a
10/05/94
Fig. 1, Wide-Band Exhaust Clamp
Exhaust
49
School Bus Chassis Maintenance Manual, October 1996
49/1
