A/C - Low Mileage or Compressor Belt Wear
86chevy16NUMBER: 86-B-90
GROUP: 6B - Cooling
DATE: June, 1986
SUBJECT: INCORRECT AIR CONDITIONING COMPRESSOR BELT
MODELS: 1985-86 M VANS EQUIPPED WITH THE 4.3L V6 ENGINE
Some 1985-86 M Vans equipped with the 4.3L V6 engine and air conditioning (A/C) may experience low mileage A/C compressor belt wear. This condition may be caused by an incorrect belt being installed during production of the vehicle. The incorrect A/C belt (3/8" x 55") has a center cordline (CCL) too low in the belt cross section which can cause overloading of the belt. Starting with 1986 GMC VIN breakpoint GB 515582, a new A/C belt (3/8" x 54.5" "High Ride")
which has a higher CCL has been released for production and service use. If this condition is encountered, replace the A/C compressor belt with P/N 469594. Tighten belt to 645 N (145 lb.) using belt tension gauge J-23600-B or BT 33-95-ACBN. Refer to the belt replacement procedures in the Light Duty Service Manual, Section 6B, Engine Cooling.