GM Service Manual Online
For 1990-2009 cars only

SEIZED A/C COMPRESSOR SERVICE PROCEDURE

When service of any seized compressor is required, it is important to accurately inspect the complete system for leaks and eliminate the cause. All hoses, connections, evaporator and condenser should be leak tested after the compressor is repaired.

Before recharging the system, the orifice tube should be removed and cleaned to remove any debris or contaminants.

When evacuating the A/C system in preparation for recharging, if a 711.2 to 736.6mm (28" to 29") vacuum cannot be held for five minutes, the system has a leak.

In all evacuation procedures, the specification of 711.2 to 736.6mm (28" to 29") vacuum is used. This specification can only be reached at or near sea level. For each 304.8m (1,000 feet) above sea level, the specification should be lowered by one inch of vacuum.

After charging, the system should be closely inspected for leaks with the most accurate leak detector available. Special attention should be given to all hoses and fittings as these are often overlooked, yet frequently are the leak source. An accumulation of dirt and oil at a fitting is a good indication of a leak. ALL leaks should be repaired prior to releasing the vehicle to avoid subsequent costly compressor repairs.

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.