Emergency repairs Noise and Emission Control
– 105 –
• Check exhaust manifold cap
screws for tightness, including
those at the flanges. Refer to the
engine manufacturer's service
manual for proper tightening
sequence and torque values.
Joints and Clamps
• Check for leaks, and tighten as
necessary. Check for deterioration
or dents in pipes and clamps which
could allow exhaust to escape.
Piping
• Check exhaust piping for rust, cor-
rosion, or damage. Replace deteri-
orated piping before holes appear.
If piping is perforated at any point,
temporary patching or lagging is
acceptable until you can have per-
manent repairs made. On turbo-
charged engines, check joints at
flanges and mounting brackets for
tightness.
Mufflers
• Check muffler, clamps, and mount-
ing brackets. Tighten if necessary.
Inspect muffler for signs of rust or
corrosion.
• Check internal baffling. You can do
this by listening for rattling sounds
while tapping the muffler with a rub-
ber mallet or revving the engine up
and down through its normal oper-
ating range.
Exhaust Tail Pipe
• Check the mounting. Tighten as
necessary. Do not modify the end
of the pipe in any way.
Engine Fan and Shroud
WARNING! Do not work on
the fan with the engine run-
ning. The engine fan can
engage at any time without
warning. Anyone near the
fan when it turns on could
be seriously injured. Before
turning on the ignition, be
sure that no one is near the
fan.
• Check all fasteners for tightness.
Check for stress cracks in the fan
and shroud. Make sure the shroud
is adjusted so that it does not touch
the fan blades.
• Check fan blade mounting bolts.
Inspect fan blades to be sure they
are not cracked or bent. If problems
exist, refer to the Cooling System
section in the maintenance manual
for detailed maintenance instruc-
tions.
PB1340A.book Page 105 Friday, September 1, 2000 7:40 AM
