Preventive Maintenance Heater and Air Conditioner
Medium Duty
(R10/06) Y53-6008 – 181 –
CAUTION: During extreme cold weather, do not
blow hot air onto cold windshields. This could
crack the glass. Turn the air direction lever to
Defrost and reduce the fan speed while the
engine warms. If the engine is already warm,
move the temperature selector to Cool, then
gradually increase the temperature when you
see that the windshield is starting to warm-up.
Air Conditioner
WARNING! The air conditioning system is under
pressure. If not handled properly during servic-
ing, it could explode, causing injury to you and
damage your vehicle. Any servicing that
requires depressurizing and recharging the air
conditioning system must be conducted by a
qualified technician with the right facilities to do
the job.
• Check the compressor and drive clutch for noise and
vibration. If you find problems, have the system checked
thoroughly. A malfunctioning clutch usually indicates
trouble elsewhere in the system.
• Check the evaporator core and condenser core for
debris restricting air flow. Clean if necessary. Small parti-
cles may be removed with compressed air blown through
the core in the opposite direction of normal air flow.
WARNING! Wear eye protection any time
you blow compressed air. Small particles
blown by compressed air could injure your
eyes.
• Check the compressor belt for condition and proper ten-
sion.
• Check all hoses for kinks, deterioration, chafing, and
leaks. Adjust kinked or chafing hoses to eliminate restric-
tions and prevent further wear.
• Check all components and connections for refrigerant
leaks. If you discover a leak, do not try to tighten a con-
nection. Tightening a connection may cause a worse
leak. Have a qualified technician correct the problem.
NOTE: A leaking evaporator or condenser core
cannot be repaired; it must be replaced.
Have the air conditioning system fully serviced annually by
your Peterbilt Dealer or Authorized Service Center. Qualified
service technicians will have to evacuate and recharge the
system.
