C 1500 Truck 2WD V8-350 5.7L (1989)
Hose/Line HVAC: All Technical Service Bulletins
A/C Compressor - Moan/Vibration/Noise
Number:
91-505-1B
Section:
1B
Date:
JUNE 1992
Corporate Bulletin No.: 061201R
ASE No.: A7
Subject:
AIR CONDITIONING COMPRESSOR MOAN/VIBRATION/NOISE
Model and Year:
1988-91 C/K TRUCKS
THIS BULLETIN CANCELS AND SUPERSEDES DEALER SERVICE BULLETIN NO. 90-382-1D, DATED NOVEMBER 1990. THE 1991
MODEL YEAR HAS BEEN ADDED AS WELL AS INFORMATION ON THE 1992 MODEL HOSES. ALL COPIES OF 90-382-1D SHOULD BE
DISCARDED.
Some 1988-1991 C/K model trucks may develop a condition described as a moan, vibration, or noise when the A/C compressor is engaged. To address
this condition, a suction discharge hose assembly has been released for service. This new hose assembly will be made of a different material, (nitrile),
than the production assembly and dampens more vibration. 1992 models, although not equipped with nitrile hoses, are equipped with hoses made of a
material with the same vibration transmission properties.
IMPORTANT:
The revised hose assembly alone will not solve all customer comments. It is essential that the revised service hose be used only after the following noise
abatement procedures have been employed.
^
Check A/C system for grounding (hoses/pipes hitting hoses/pipes, body or engine).
^
Check mounting bolts for being loose, missing, or a blind hole.
^
Check drive belt for debris in the grooves or for wear
^
Check that a brace kit has been installed from Dealers Service Bulletin No. 88-82-1B or Dealer Service Bulletin No. 91-435-1D.
^
Check that the latest R4 compressor is being used. All 1990 and 1991 Model C/K trucks were built with the latest style A/C compressor. When
repairing 1988 and 1989 model C/K trucks, reference Dealer Service Bulletin 89-280-1B.
^
To determine whether the new nitrile hose assembly will lessen the A/C noise-moan-vibration, have a person in the cab listen to the noise at the
engine speed where the noise is most prevalent. Have another person in front of the truck grab the suction hose with both hands. This will
approximate the noise reduction which will result from replacement of the hose.
SERVICE PARTS INFORMATION
Nitrile Hose Assembly
Part Number
Application
Quantity
15551664
1988-89 C/K with LB4 (4.3L V6)
1
15551665
1988-89 C/K with L03/L05 (5.0L or 5.7L V8)
1
15551666
1988-89 C/K with L19 (7.4L V8)
1
15551667
1988-89 C/K with LH6/LL4 (6.2L V8 diesel)
1
15551668
1990-91 C/K with LB4 (4.3L V6)
1
15551669
1990-91 C/K with L03/LO5 (5.0L or 5.7L V8)
1
15551670
1990-91 C/K with L19 (7.4L V8)
1
15551671
1990-91 C/K with LH6/LL4 (6.2L V8 diesel)
1
Parts are currently available at GMSPO.
WARRANTY INFORMATION
