GROWL NOISE DURING A/C OPERATION (CHECK - LEAKS ETC.)

Subject: GROWL NOISE DURING AIR CONDITIONING OPERATION

Model and Year: 1992-93 SUBURBAN WITH REAR AIR CONDITIONING (RPO C69)

CONDITION:

--------- Owners of some 1992 and 1993 Suburbans with C69 (rear air conditioning) may comment on a noise (growl/pumping) during A/C operation (usually at idle and above engine speeds).

CAUSE:

----- Low charge due to leaks, improper initial charge, or system sensitivity to amount of charge.

CORRECTION:

---------- 1. Thoroughly check A/C system for refrigerant leaks.

2. Repair any and all leaks found.

3. Evacuate/purge the system of its refrigerant charge.

4. Recharge the system with 4 1/2 lbs (72 oz.) of refrigerant (vehicle label says 4 1/4 lbs (68 oz.)

IMPORTANT: Do not assume the vehicle has a full charge of 68 oz. and add 4 oz. Fully evacuate the system and recharge with 72 oz. of R12.

Specific instructions on evacuation and charge can be found in Section 1 B of Light Duty Truck service manual.

WARRANTY INFORMATION:

For vehicles repaired under warranty, use:

LABOR OP LABOR TIME -------- ---------- T7631 1.0 hr.

Labor operation includes leak check, evacuation, and recharge. Consult the Labor Time Guide for the appropriate labor operation if leak repairs were necessary.

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.