Peterbilt Medium Duty Trucks Operator's Manual after 1-07

Preventive Maintenance
Engine
• Removing or rendering engine speed governor inoperative
so as to allow engine speed to exceed manufacturer's
specifications.
• Modifying ECU parameters.
Exhaust System
• Removing or rendering inoperative exhaust system components.
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 systems
and components, it is found that parts of the noise control
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.
Noise and Emission Control
• 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 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.
Medium Duty (R10/06) Y53-6008 – 221 –