MOAN NOISE WITH A/C ON INSTALL NEW COMPRESSOR PULLEY

Model and Year: 1985-88 LIGHT DUTY TRUCKS AND VANS WITH R-4 A/C COMPRESSOR AND WITHOUT SERPENTINE BELT DRIVE

TO: ALL CHEVROLET DEALERS

Chevrolet Dealer Service Bulletin 88-176-1 B dated March, 1988 is being cancelled and superseded by this bulletin to include "P" model trucks. All copies of 88-176-1 B should be discarded.

An A/C moan on vehicles equipped with one of the engines listed below can be addressed by replacing the A/C compressor pulley.

NOTICE: Prior to ordering the new pulley, visual verification should be made that the vehicle is equipped with the R-4 compressor and is not serpentine belt driven.

YEAR MODELS ENGINES ---- ------ -------- 1985 C/K 4.3L 5.0L 5.7L 6.2L Diesel M 4.3L G 4.3L 5.0L 5.7L P 4.8L 5.7L

1986 C/K/P 4.3L 5.0L 5.7L M 4.3L G 4.3L 5.0L 5.7L

1987 R/V/P 4.3L 5.0L 5.7L G 5.7L (LT9 ONLY)

1988 R/V/P 5.0L 5.7L G 5.7L (LT9 ONLY)

The new pulley, P/N 6552402, is a single "V" groove high inertia pulley, which is heavier than the original "V" groove pulley.

Refer to Section 1 B of the appropriate service or unit repair manual for removal and installation procedures.

Parts and currently available from GMSPO.

For repair to vehicles under warranty, use:

Labor Operation: D4280

See Labor Time Guides for applicable times on individual model applications.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.