Inspection of the Air Conditioner

1. Park the vehicle on a level surface, shut down the engine, and set the parking brake. Chock the tires.
2. Operate the heater and, if so equipped, the air conditioner, to check for proper operation in all modes.
3. Open the hood.
4. Check the condition of the refrigerant compressor clutch assembly for visible signs of damage due to excessive heat. 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, and replace it if necessary.
6. Check the tightness of the compressor mounting fasteners. The torque value for the mounting fasteners 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 not turn freely, the compressor should be replaced. For instructions, see the applicable section, see  of the vehicle Workshop Manual , or take the vehicle to an authorized Freightliner dealer.
8. Using a feeler gauge, 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 the applicable section, see  of the vehicle Workshop Manual , or take the vehicle to an authorized Freightliner dealer.
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 condenser fins. Using air pressure and a whisk broom or a soapy spray of water, carefully clean the condenser. Be careful not to bend the fins.
12. Close the hood.