For 1990-2009 cars

# 'O' RING IDENTIFICATION CHART AIR CONDITIONING

#### Models Affected: ALL MODELS

The attached chart is an easy to use "O" Ring Identification Chart. It includes the actual "O" Ring size, color and part number.

The reverse side of the chart has an Air Conditioning Reference Chart. It also shows the installation procedures for installing a Liquid Line Filter.

AIR CONDITIONING SERVICE

TESTING THE REFRIGERANT SYSTEM

IF A MALFUNCTION IN THE REFRIGERANT SYSTEM IS SUSPECTED DUE TO ABNORMAL SYSTEM PRESSURES, CHECK THE FOLLOWING:

1. CHECK OUTER SURFACES OF RADIATOR AND CONDENSER CORES TO BE SURE AIR FLOW IS NOT BLOCKED BY DIRT, LEAVES, OR OTHER FOREIGN MATERIAL. BE SURE TO CHECK BETWEEN THE CDNDENSER AND RADIATOR AS WELL AS THE OUTER SURFACES,

2. RESTRICTIONS OR KINKS IN EVAPORATOR CORE OR CONDENSER CORE, HOSES, TUBES, ETC.

3. REFRIGERANT LEAKS. OIL TRACES ARE CLUES.

4. CHECK ALL AIR DUCTS FOR LEAKS OR RESTRICTIONS. LOW AIR FLOW RATE MAY INDICATE A RESTRICTED OR ICED EVAPORATOR CORE.

5. COMPRESSOR CLUTCH SLIPPAGE.

6. IMPROPER DRIVE BELT TENSION.

7. PLUGGED ACCUMULATOR OR EXPANSION (ORIFICE) TUBE.

8. EXCESSIVE MOISTURE IN REFRIGERANT SYSTEM.

REFRIGERANT-12 CHECK

THE FOLLOWING PROCEDURE CAN BE USED TO OUICKLY DETERMINE WHETHER OR NOT THE A/C SYSTEM HAS THE PROPER CHARGE OF REFRIGERANT-12 (PROVIDING AMBIENT TEMPERATURE IS ABOVE 21 DEG C (70 DEG F). THIS CHECK CAN BE MADE IN A MATTER OF MINUTES, SIMPLIFYING SYSTEM DIAGNOSIS BY PINPOINTING THE PROBLEM TO THE AMOUNT OF R-12 CHARGE IN THE SYSTEM OR BY ELIMINATING LOW CHARGE POSSIBILITY FROM THE OVERALL CHECKOUT.

1. START ENGINE AND ALLOW TO WARM UP. OPERATE AT 1000 RPM.

2. HOOD AND BODY DOORS OPEN.

3. SET SYSTEM TO MAX. COLD

4. "HAND-FEEL" TEMPERATURE OF EVAPOWOR INLET PIPE AFTER ORIFICE, AND ACCUMULATOR SURFACE, WITH COMPRESSOR ENGAGED.

A. BOTH SAME TEMPERATURE AND BOTH SAME DEGREE COOLER THAN AMBIENT-PROPER CONDITION.

B. INLET PIPE COOLER THAN ACCUMULATOR SURFACE-LOW REFRIGERANT CHARGE.

- DISCHARGE, EVACUATE AND CHARGE A/C SYSTEM TO PROPER CHARGE LEVEL SPECIFIED IN SERVICE MANUAL.

HANDLING REFRIGERANT-12

AIR CONDITIONING SYSTEMS CONTAIN REFRIGERANT-12. THIS IS A CHEMICAL MIXTURE WHICH REQUIRES SPECIAL HANDLING PROCEDUES TO AVOID PERSONAL INJURY.

ALWAYS WEAR GOGGLES AND WRAP A CLEAN CLOTH AROUND FITTINGS, VALVES, AND CONNECTIONS WHEN PERFORMING WORK THAT INVOLVES OPENING THE REFRIGERANT SYSTEM. ALWAYS WORK IN A WELL VENTILATED AREA AND DO NOT WELD OR STEAM CLEAN ON OR NEAR ANY AIR CONDITIONING LINES OR COMPONENTS.

IF REFRIGERANT-12 SHOULD COME IN CONTACT WITH ANY PART OF THE BODY, FLUSH THE EXPOSED AREA WITH COLD WATER AND IMMEDIATELY SEEK MEDICAL HELP.

ALL REFRIGERANT-12 DRUMS ARE SHIPPED WITH A HEAVY METAL SCREW CAP. THE PURPOSE OF THE CAP IS TO PROTECT THE VALVE AND SAFETY PLUG FROM DAMAGE. IT IS GOOD PRACTICE TO REPLACE THE CAP AFTER EACH USE OF THE DRUM FOR THIS SAME REASON.

IF IT IS NECESSARY TO TRANSPORT OR CARRY ANY CONTAINER OF REFRIGERANT-12 IN A VEHICLE, DO NOT CARRY IT IN THE PASSENGER CDMPARTMENT.

IF THE OCCASION ARISES TO FILL A SMALL REFRIGERANT-12 DRUM FROM A LARGER ONE, NEVER FILL THE DRUM CDMPLETELY. SPACE SHOULD ALWAYS BE ALLOWED ABOVE THE LIQUID FOR EXPANSION.

THE FOLLOWING GENEPAL PRACTICES SHDULD BE OBSERVED TO INSURE CHEMICAL STABILITY IN THE SYSTEM.

1. BEFORE DISCONNECTING A REFRIGERANT CONNECTION, WIPE AWAY ANY DIRT OR OIL AT AND NEAR THE CONNECTION TO REDUCE THE POSSIBILITY OF DIRT ENTERING THE SYSTEM. BOTH SIDES OF THE CONNECTION SHOULD BE CAPPED, PLUGGED, OR TAPED AS SOON AS POSSIBLE TO PREVENT THE ENTRY OF DIRT, FOREIGN MATERIAL, AND MOISTURE.

2. KEEP TOOLS CLEAN AND DRY. THIS INCLUDES THE MANIFOLD GAGE SET AND REPLACEMENT PARTS.

3. WHEN IT IS NECESSARY TO "OPEN" AN A/C SYSTEM, HAVE EVERYTHING NEEDED READY AND HANDY SO THAT AS LITTLE AS POSSIBLE WILL BE REQUIRED TO PERFORM THE OPERATION. DO NOT LEAVE THE A/C SYSTEM OPEN ANY LONGER THAN IS NECESSARY.

OIL REPLACEMENT

1. ALWAYS TRAP OIL IN A BOTTLE WHEN DISCHARGING A SYSTEM AND REPLACE THE SAME QUANTITY OF NEW, CLEAN REFRIGERANT OIL BEFORE RECHARGING.

2. WHEN REPLACING A COMPONENT (CONDENSER, EVAPORATOR ACCUMULATOR, ETC.), ALWAYS ADD CLEAN NEW OIL TO THE NEW COMPONENT AS SPECIFIED IN THE SERVICE MANUAL.

3. WHEN REPLACING A COMPRESSOR, FOLLOW SERVICE MANUAL INSTRUCTIONS TO MAINTAIN THE CORRECT OIL QUANTITY IN THE SYSTEM.

LIQUID LINE FILTER INSTALLATION

(FOR VEHICLES WHICH DO NOT HAVE AN INTEGRAL LIQUID LINE FILTER AVAILABLE)

1. AFTER LOCATING THE FILTER IN THE LIQUID LINE, CUT OFF A SECTION OF THE LIQUID LINE WHICH IS APPROXIMATELY 1" LESS THAN THE LENGTH OF THE FILTER WITH A SHARP TUBING CUTTER.

2. WEDGE A SMALL CLOTH BALL INTO BOTH ENDS OF THE CUT LIQUID LINE TO PREVENT PARTICLES FROM ENTERING THE A/C SYSTEM.

3. FILE AWAY THE EXTERNAL BURR.

4. CUT OUT THE INTERNAL BURR.

5. CAREFULLY REMOVE THE CLOTH BALLS FROM THE LIOUID LINE REMOVING ALL LOOSE PARTICLES WHICH MAY HAVE ACCUMULATED FROM STEPS 3 AND 4.

6. PLACE THE NUT OVER THE CONDENSER END OF THE CUT LIQUID LINE, THEN INSTALL THE FERRULE WITH THE SMALL END TOWARD THIS NUT (SEE FIG. 1).

7. REMOVE "O" RING FROM THE INLET SIDE OF THE FILTER, LUBRICATE WITH REFRIGERANT OIL AND REINSTALL IF SO EQUIPPED AND INSERT THE TUBE INTO THE COMPRESSION FITTING OF THE FILTER UNTIL IT BOTTOMS OUT, THEN TIGHTEN THE NUT TO THE SPECIFIED TORQUE.

8. REPEAT STEPS 6 AND 7 TO THE EVAPORATOR END OF THE CUT LIQUID LINE AND THE OUTLET SIDE OF THE FILTER.

9. REFORM THE LIQUID LINE AS REQUIRED, TAKING CARE NOT TO CRUSH OR DEFORM THE LINE, CAUSING A RESTRICTION IN THE A/C SYSTEM.

10. IF THE FILTER IS INSTALLED IN A LOCATION WHICH MAY ALLOW CONTACT WITH ANY PART OF THE VEHICLE, THE FILTER SHOULD BE WRAPPED IN CLOSED CELL FOAM RUBBER.

11. CHECK COMPRESSION FITTINGS FOR LEAKS AFTER EVACUATING AND CHARGING THE A/C SYSTEM.

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.