A SERVICE OF

logo

Preventive Maintenance Noise and Emission Control
Medium Duty
(R10/06) Y53-6008 – 221 –
Engine
Removing or rendering engine speed governor inopera-
tive so as to allow engine speed to exceed manufac-
turer's specifications.
Modifying ECU parameters.
Exhaust System
Removing or rendering inoperative exhaust system com-
ponents.
Inspection and Maintenance Instructions
The following instructions are based on inspection of the
noise control system at regular intervals.
If, during periodic inspection and maintenance of other sys-
tems and components, it is found that parts of the noise con-
trol system require attention, we recommend that those parts
be inspected at more frequent intervals to assure adequate
maintenance and performance.
Air Intake System
Do all checks and maintenance procedures listed in this
manual under Engine Air Intake System and Air Cleaner.
See “
Air Intake System” on page 166.
Check the induction tubing, elbow connections, clamps,
brackets, and fasteners for deterioration, cracks, and
security.
If you find an air leak anywhere between the air cleaner
and the engine, repair that leak immediately.
CAUTION: Air leaks cause excessive noise and
may result in serious damage to the engine. If
you do not repair them the engine damage will
not be covered by your warranty. Repair all air
leaks as soon as you find them.
Exhaust System
Check for exhaust leaks, which would indicate a leaking
manifold gasket; replace gasket if necessary.
Check cap screws for tightness, including those at the
flanges. Refer to the engine manufacturer's service man-
ual 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.