Preliminary Checks
cen mm 83.01.000
- Park the vehicle on a level surface, apply the parking brakes, and chock the tires.
- Check the appearance of the refrigerant compressor pulley 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. 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 fasteners. For instructions and torque values, see of the Century Class Trucks Workshop Manual.
- 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 instructions, see of the Century Class Trucks Workshop Manual.
- On a Sanden refrigerant compressor, use a feeler gauge
to check that the drive plate clutch clearance is 0.016 to 0.031 inch
(0.40 to 0.78 mm). See Fig.. If the drive plate clutch requires adjustment, see of the Century Class Trucks
Workshop Manual.On a Climate Control refrigerant compressor, place a feeler gauge between the air conditioner compressor clutch and the pulley to check the compressor clutch clearance. Drive plate to pulley clearance should be 0.020 to 0.030 inch (0.50 to 0.76 mm). If the clearance is 0.035 inch (0.89 mm) or greater, replace the clutch. For instructions, see of the Century Class Trucks Workshop Manual.
Fig. 1, Drive Plate Clearance Inspection
- Inspect the compressor clutch coil wire. Check that the connector is not damaged or loose. Replace the wire if it is damaged.
- Check the overall condition of the air conditioning hoses. Look for cracks, cuts, and abrasions on the hoses. Replace damaged hoses. Check for loose fittings on all of the air conditioning components.
- Check for road debris buildup on the condenser 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.
Warning: Wear eye protection, gloves, and protective clothing when working on the air conditioning system. Leaking refrigerant from a damaged hose or line could cause blindness or serious skin burns.
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