A/C Compressor - Moan Noises Under Light Acceleration
File In Section: 1 - HVACBulletin No.: 43-12-25A
Date: June, 1996
Subject:
A/C Compressor Moan Noise Under Light Acceleration (Replace A/C Compressor Hose Assembly and Clutch Driver)
Models:
1992-93 Cadillac Eldorado, Seville
1994 Cadillac DeVille
Engine Applications:
This bulletin is being revised to include the 1992-93 E/K models. Please discard Corporation Bulletin Number 43-12-25 (Section 1 - HVAC).
Condition
Some owners may comment on an A/C compressor moan noise that becomes evident under light acceleration when the A/C compressor clutch is engaged. This condition is more likely to exist in high ambient temperature/humidity and be most repeatable under light acceleration between 1400 and 2100 engine RPM.
Cause
The compressor hose assembly transmits the compressor pumping pulses into the body. The material of the compressor hose does not provide sufficient dampening causing the transmittal of these noises.
Correction
To determine the correct cause of the moan noise, the following steps must be followed:
1. Check the torque of the mounting bracket to engine. Check the torque of the A/C compressor to the mounting bracket.
2. Check that no A/C hoses are touching other components. Common ground points are:
^ Low side to right strut tower
^ Low side to battery tray or routing clip
^ High side to ABS valve assembly
^ Condenser inlet or outlet pipes to radiator, body or wire harness
^ High side to plastic cover (driver's side underhood)
^ High side to body wire harness near brake booster
3. Replace the A/C compressor hose assembly with new hose (see below for P/N). The hose material used in this assembly is softer. Refer to Section 1B of the Service Manual for replacement procedure.
4. Replace the A/C compressor clutch driver with the dampened type using kit, P/N 6553791. Refer to Section 1D2 of the Service Manual for replacement procedure.
Important:
This clutch must be cycled 50 times to assure optimal performance.
Parts Information
Parts are currently available from GMSPO.
Warranty Information
For vehicles repaired under warranty, use as shown.