If you lack the proper tools, training, and knowledge, take your vehicle to a qualified mechanic. This is the safest and most reliable approach.
However, if you're determined to proceed, here's a *general* overview. Again, this is for informational purposes only and does not constitute a recommendation to do this yourself.
Tools and Equipment Required (Minimum):
* A/C Manifold Gauge Set: This is absolutely crucial for monitoring pressure and ensuring proper evacuation.
* Vacuum Pump: Necessary to evacuate the system completely before recharging.
* Refrigerant Recovery Tank: Required by law in most places to recover refrigerant for proper disposal. Do not vent refrigerant into the atmosphere.
* Safety Glasses and Gloves: Protect yourself from potential hazards.
* Wrench(es): To access the low-side service port (usually on the drier/accumulator).
* Properly sized hose and fittings that are compatible with your refrigerant.
General Steps (Highly Simplified and Dangerous if not properly performed):
1. Locate the Low-Side Service Port: This is usually on the accumulator/drier.
2. Connect the Manifold Gauge Set: Attach the hoses to the low-side port and the recovery tank. Ensure the gauges are properly installed and sealed.
3. Evacuate the System: Turn on the vacuum pump to draw a vacuum within the A/C system. This removes the remaining refrigerant and moisture. The vacuum should be maintained for at least 30 minutes to ensure proper evacuation. Monitor the vacuum gauge closely.
4. Recover the Refrigerant: Use the manifold gauge set to recover the refrigerant into the recovery tank. Follow the instructions on your recovery tank and manifold gauge set precisely.
5. Once the system is empty (indicated by the gauges), close the service port.
Important Considerations:
* Refrigerant Type: Determine whether your 1994 Suburban uses R-12 (older) or R-134a (more common in later years). Using the wrong refrigerant can damage the system. Consult your owner's manual or a qualified mechanic.
* Disposal: Proper disposal of the recovered refrigerant is essential. Take the recovery tank to a licensed auto repair shop or recycling center.
* Oil: The system will likely need oil added after a complete drain and recharge. This is highly dependent on whether or not any components were replaced.
Again, this is a very simplified and dangerous procedure. Improper handling of refrigerant can result in serious injury or death. If you are not experienced with automotive A/C systems, please take your vehicle to a professional. They have the necessary equipment, training, and knowledge to safely and correctly service your A/C system.
