However, if you're determined to do it yourself, here's a general outline. This is *not* a complete, step-by-step guide, and specific procedures will vary depending on the engine and AC system configuration of your particular Regal. Always consult a repair manual specific to your vehicle's year, make, and model.
Before You Begin:
* Safety First: Wear safety glasses and gloves. Refrigerant is dangerous.
* Recovery and Recycling: You must recover the refrigerant from the system using a proper AC recovery machine. Releasing it into the atmosphere is illegal and harmful. Rent or borrow one if you don't own one.
* Repair Manual: Obtain a factory service manual or a reputable aftermarket repair manual specific to your 1991 Buick Regal. This is essential for detailed instructions and torque specifications.
* Tools: You'll need various tools, including wrenches, sockets, screwdrivers, a refrigerant recovery machine, AC manifold gauges, vacuum pump, and possibly a compressor clutch tool.
General Steps (This is NOT a comprehensive guide):
1. Disconnect the Battery: Disconnect the negative battery cable to prevent electrical shorts.
2. Recover Refrigerant: Use your AC recovery machine to safely evacuate the refrigerant from the system.
3. Release System Pressure: After recovery, double-check that the system pressure is zero using the manifold gauges.
4. Access the Compressor: This will involve removing various components, potentially including:
* Serpentine belt (and possibly tensioner).
* Various hoses and lines connected to the compressor. Be sure to mark and label them carefully to avoid incorrect reinstallation.
* Compressor mounting brackets.
5. Disconnect Components: Carefully disconnect all hoses and electrical connectors from the compressor. Note the position and routing of everything.
6. Remove the Compressor: Remove the compressor from its mounting brackets. This may require removing the entire assembly or only certain parts depending on the vehicle's design.
7. Install the New Compressor: Install the new compressor, ensuring it's properly seated and bolted.
8. Reconnect Components: Carefully reconnect all hoses and electrical connectors, paying close attention to the labeling you did earlier.
9. Reinstall Belt and Components: Reinstall the serpentine belt, tensioner, and any other components you removed.
10. Evacuate and Charge System: Use the vacuum pump to evacuate the system to remove any air and moisture. Then, charge the system with the correct amount and type of refrigerant as specified in your repair manual. Use the manifold gauges to monitor pressure.
11. Test the System: Start the engine and test the AC system for proper operation.
Important Considerations:
* O-rings and Seals: Replace all O-rings and seals on the hoses and connections when reassembling the system. These are critical for preventing leaks.
* Clutch Alignment: The compressor clutch needs to be properly aligned during reinstallation.
* Refrigerant Type: Use the correct type and amount of refrigerant specified for your vehicle.
* Disposal: Dispose of the old compressor and refrigerant properly according to local regulations.
Again, this is a simplified overview. Attempting this repair without proper training and tools is risky. Professional assistance is strongly advised. A faulty repair could damage your AC system further, costing significantly more in the long run. Consult your repair manual and/or a qualified mechanic.
