83–00 Safety Precautions
Safety Precautions in this section apply to all
procedures within this group.
DANGER
When working on the vehicle, shut down the en-
gine, set the parking brake, and chock the tires.
Before working under the vehicle, always place
jack stands under the frame rails to ensure the
vehicle can not drop. Failure to follow these steps
could result in serious personal injury or death.
83–01 Air Conditioner
Inspection
WARNING
Wear eye protection, gloves, and protective cloth-
ing when working on the air conditioning system.
Leaking refrigerant from a damaged hose or line
could cause blindness or serious skin burns.
Preliminary Checks
1.
Park the vehicle on a level surface, apply the
parking brakes, and chock the tires.
2.
Check the appearance of the air conditioner
compressor pulley assembly. If the friction sur-
face of the pulley shows signs of excessive
grooving due to belt slippage, replace both the
pulley and the drive plate. Inspect the refrigerant
compressor drive belt for damage and check that
the belt is set at the proper tension. Also check
the tightness of the compressor mounting fasten-
ers. For instructions and torque values, see
Group 01
of the
Cascadia
™
Workshop Manual
.
3.
Inspect the drive plate. If the drive plate shows
visible signs of damage due to excessive heat,
replace the drive plate and pulley assembly. For
removal and installation procedures, see
Group
83
of the
Cascadia
™
Workshop Manual
.
4.
Using a feeler gauge, check that the drive plate
clutch clearance is within limits. See
Table 1
for
clearance specifications. See
Fig. 1
for the
checking method. If the drive plate clutch re-
quires adjustment, see
Group 83
of the
Casca-
dia
™
Workshop Manual
.
Compressor Drive-Plate Clutch Clearance
Manufacturer
Clearance: in (mm)
Sanden
0.016 to 0.040 (0.4 to 1.0)
Denso
0.014 to 0.024 (0.35 to 0.60)
Table 1, Compressor Drive-Plate Clutch Clearance
5.
Inspect the compressor clutch coil wire. Check
that the connector is not damaged or loose. Re-
place the wire if it is damaged.
6.
Check the overall condition of the air conditioning
hoses. Look for cracks, cuts, and abrasions on
the hoses. Replace damaged hoses. For re-
placement instructions, see
Group 83
of the
Cascadia
™
Workshop Manual
. Also check for
loose fittings on all of the air conditioning compo-
nents.
7.
Check for a buildup of road debris on the con-
denser fins. For cleaning instructions, see
Group
83
of the
Cascadia
™
Workshop Manual
.
83–02 Air Filter Replacement
The HVAC system has three filters that must be re-
placed periodically to maintain proper system opera-
tion. The cabin fresh-air-intake filter is accessed from
under the hood, and the recirculation filter is ac-
cessed from inside the cab. The sleeper air filter is
accessed through an access panel on the cabinet
behind the driver’s seat.
08/25/94
f830641
Check clearance in three equally spaced places.
Fig. 1, Drive-Plate Clearance Inspection
Heater and Air Conditioner
83
Cascadia Maintenance Manual, August 2015
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