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Replace Air Conditioner Compressor

Air Conditioner Compressor

How to Replace an Air Conditioner Compressor

Before you attempt to replace your air conditioning compressor there are a few things to consider. The refrigerant inside the air conditioning system is under high pressure and should not be released directly into the atmosphere. The refrigerant is hazardous, expensive and recyclable. Recovery of the refrigerant should only be done with a recovery/recycling/charging station that matches the refrigerant used in your vehicle. 1993 and older vehicles usually use R12 and 1994 and newer vehicles use R-134a. Use a refrigerant charging station to recover the refrigerant. R12 and R-134a are not compatible and should never be mixed. Refer to a repair manual to confirm which refrigerant you have and which is the high and low side of the compressor before you attempt this repair. Once finished with the compressor replacement, you can re-use the old refrigerant using the same charging station.

Before you begin work, park your car on a flat surface with the emergency brake on. Engine must be cold. Wear protective clothing, gloves and eyewear.

Step 1 - Loosen and remove the negative battery cable from the battery. Secure cable so it will not contact the negative battery post at any time during the repair. Note: Before disconnecting the battery, make sure you have written down your anti-theft and radio codes. They will both have to be reset after you reconnect the battery.


Step 2 - Start by locating and connecting the high-pressure service port and low pressure service port to the recovery station. A small amount of refrigerant oil will be removed along with the refrigerant, make sure to replace the same amount of oil before recharging the system. Refrigerant oil is susceptible to moisture contamination so be sure to use only fresh refrigerant oil.

Step 3 - Remove the serpentine belt, covers or accessories like a alternator to gain access to the compressor if needed. By documenting your steps as you remove covers and parts, you can follow the steps in reverse to re-assemble. Check the condition of your drive belt and replace if necessary.

Step 4 - Remove the fan mounting bolts and electrical connector and remove the fan or fan clutch from the fan shroud.

Step 5 - Use a catch pan under vehicle and remove and radiator hoses as needed, engine coolant will spill out.

Step 6 - Next, remove the fan shroud to allow enough room to access air conditioner compressor. Always take care when working around the radiator cooling fins, they can be sharp and can injury.

Step 7 - Disconnect the discharge line and the suction line from the air conditioning compressor. Make sure to plug or cap the lines as soon as possible to minimize and contamination or moisture entering the system.

Step 8 - Now, you can remove the air conditioning compressor mounting bolts and remove the compressor taking care not to bump the radiator cooling fins.

Step 9 - Compare the old and replacement compressor to make sure they are identical.

Step 10 - Install the replacement compressor and tighten all bolts.

Step 11 - Before connecting the high and low pressure fittings make sure to replace the sealing o-rings with new ones. Put a small amount of refrigerant oil on the o-rings prior to installation, they should be completely covered with oil. Connect the high and low pressure fittings to the compressor.

Step 12 - Re-install the fan shroud and attach fan clutch or electric fan.

Step 13 - Re-install radiator hoses and add coolant to the radiator and recovery tank.

Step 14 - Re-install alternator or other accessories removed to gain access.

Step 15 - Install covers and serpentine drive belt.

Step 16 - Re-connect battery.

Step 17 - Before re-charging the system; make sure to evacuate the system completely. Check the refrigerant capacity to make sure you do not over fill the system, too much refrigerant can hurt cooling efficiency as much as having too little refrigerant can. If the vacuum reading isn’t more than 93.3 kPa in 15 minutes, there is more than likely a leak somewhere in the system. Only recharge using the low side pressure fitting. Once a leak is located you will need to evacuate the system before attempting to repair it.

Step 18 - When charging the system be sure to replace the same amount of oil that was removed during the refrigerant recovery process.

Step 19 - Charge system with the manufacturers recommended amount of refrigerant. Over charging the system will damage the air conditioning compressor.

Step 20 - Use refrigerant leak detector to make sure no refrigerant leaks are present.

Step 21 - Program the anti-theft codes for the navigation system and radio. All radio station presets will have to be entered again as well.

If further assistance is needed, our certified car repair technicians are ready to answer your car questions. Also, gain manufacturer specific instructions and information by clicking - Auto Repair Manual

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