freightliner COLUMBIA CL112 Maintenance Manual page 120

Heater and Air Conditioner
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 Columbia
3. Inspect the drive plate. If the friction surface of
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 Columbia
Workshop Manual .
4. On a Sanden A/C compressor, use a feeler
gauge to check that the drive plate clutch clear-
ance is 0.016 to 0.030 inch (0.4 to 0.8 mm). See
Fig. 1. If the drive plate clutch requires adjust-
ment, see Group 83 of the Columbia
Manual .
On a Climate Control A/C compressor, place a
feeler gauge between the air conditioner com-
pressor clutch and the pulley to check the com-
pressor clutch clearance. Drive plate to pulley
clearance is 0.020 to 0.030 inch (0.6 to 0.8 mm).
If the clearance is not correct, see Group 83 of
the Columbia ® Workshop Manual .
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
Columbia Maintenance Manual, October 2002
® Workshop Manual .
®
® Workshop
08/25/94
Fig. 1, Drive Plate Clearance Inspection
the hoses. Replace damaged hoses. For re-
placement instructions, see Group 83 of the
®
Columbia 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 Columbia ®
Refrigerant Checking
Check the color of the moisture indicator on the
receiver-drier. See Fig.
If the indicator is blue, the refrigerant charge is dry.
If the indicator is not blue, the system is contami-
nated with water. If the system is contaminated, the
refrigerant must be recovered and the receiver-drier
must be replaced. For instructions, see Group 83 of
the Columbia ® Workshop Manual .
83–02 Air Filter Replacement
Cab Fresh Air Filter
Replacement, Blend Air
If the vehicle is equipped with a cab fresh air filter, it
must be replaced every six months regardless of
mileage to permit proper operation of the HVAC
system.
CAUTION
If equipped with a fresh air filter, it should be re-
placed every six months. If the fresh air filter is
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