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 cannot drop. Failure to follow these steps
could result in serious personal injury or death.
83–01 Air Conditioner
Inspecting
Refrigerant Compressor
Inspection
1.
With the vehicle parked on a level surface, apply
the parking brakes and chock the tires.
2.
Operate the heater and, if equipped with an air
conditioner, the air conditioner to check for
proper operation in all modes.
3.
Open the hood.
4.
Check the condition of the refrigerant compres-
sor clutch assembly. If the friction surface of the
pulley shows signs of excessive grooving due to
belt slippage, replace both the pulley and the
drive plate.
5.
Inspect the refrigerant compressor drive belt for
damage. If needed, replace the drive belt.
6.
Check the tightness of the compressor mounting
fasteners. The torque value for the mounting fas-
teners is 15 to 19 lbf·ft (20 to 26 N·m).
7.
Inspect the drive plate. If the friction surface of
the drive plate shows visible signs of damage
due to excessive heat, make sure the refrigerant
compressor turns freely. If the compressor does
turn freely, replace the drive plate and clutch as-
sembly. For instructions, see
Section 83.01
,
Subject 140 of the
Business Class® M2 Work-
shop Manual
. If the compressor does not turn
freely, replace the compressor. For instructions,
see
Section 83.01
, Subject 120 of the
Business
Class® M2 Workshop Manual
8.
Use a feeler gauge to check that the drive plate
clutch clearance is 0.016 to 0.031 inch (0.4 to
0.8 mm). If the gap is not even around the
clutch, gently tap down at the high areas. If the
overall gap is out of spec, remove the drive plate
assembly and change the shims as necessary.
For instructions, see
Section 83.01
, Subject 140
of the
Business Class® M2 Workshop Manual
.
9.
Check that the wiring harness connector is not
damaged or loose. Replace the wiring harness if
it is damaged.
10. Check the overall condition of the air conditioning
hoses. Look for cracks, cuts, and abrasions on
the hoses. Replace damaged hoses.
11. Check for a buildup of road debris on the con-
denser fins. Using air pressure and a whisk
broom or a soapy spray of water, carefully clean
off the condenser. Be careful not to bend the
fins.
12. Check the moisture indicator on the receiver-
drier. See
. If the indicator is a deep cobalt
blue, the refrigerant charge is dry. If the indicator
is not blue, the system is contaminated with
water. If the system is contaminated, recover the
refrigerant, replace the receiver drier, evacuate
the system, and add a full refrigerant charge. For
instructions, see
Section 83.00
, Subject 220 of
the
Business Class® M2 Workshop Manual
.
13. Close the hood and remove the chocks from the
tires.
83–02 HVAC Air Filter
Replacing
The HVAC air filter must be replaced every six
months or 60,000 miles (97 000 km) to permit proper
operation of the HVAC system.
1.
With the vehicle parked, apply the parking
brakes, and chock the tires.
2.
Remove the lower HVAC cover in the cab. For
instructions, see
Group 60
of the
Business
Class® M2 Workshop Manual
.
3.
Disconnect the wiring harness from the evapora-
tor probe.
4.
Remove the capscrews that attach the evapora-
tor service cover to the HVAC assembly. Remove
the evaporator service cover.
Heater and Air Conditioner
83
Business Class M2 Maintenance Manual, August 2015
83/1
Property of American Airlines