However, if you're determined to attempt it yourself, understand the risks and follow these *general* steps. Remember, these are simplified and may not be entirely accurate for your specific van's system. Consult a repair manual specific to your 1989 Chevy G20 for detailed instructions and safety precautions.
General Steps (Do NOT attempt without proper training and equipment):
1. Leak Detection: Before adding refrigerant, you MUST find and repair any leaks. A leak detection kit with UV dye is typically used. The dye is injected into the system, and a UV light is used to find leaks. Leaks need to be repaired before adding refrigerant.
2. Vacuuming the System: This is crucial. A vacuum pump is used to evacuate the system of air and moisture. This prevents contamination and ensures proper system function. The system must be held under vacuum for a specified time (consult your repair manual) to ensure proper evacuation.
3. Refrigerant Charging: This requires specialized equipment including gauges to monitor pressure and temperature, and possibly an electronic refrigerant scale for accurate charging. The type and amount of refrigerant needed are specific to your vehicle's system. Incorrect refrigerant or amount can damage the compressor. Your repair manual will specify the correct refrigerant and charge amount. Charging is typically done in stages, monitoring pressures at each step.
4. System Operation Check: After charging, run the AC system and check the temperature at the vents. Also monitor the pressure gauges to ensure the system is operating within the correct parameters.
Necessary Equipment (Professional-Grade):
* Refrigerant (R12 or R134a – check your van’s specifications. R12 is likely, but conversions to R134a are common): Handle with extreme care.
* Vacuum Pump: To evacuate the system.
* Manifold Gauge Set: To monitor system pressure.
* Leak Detection Kit (UV dye): To locate leaks.
* Refrigerant Charging Hoses: To connect to the system.
* Safety Glasses and Gloves: To protect yourself from refrigerant and other hazards.
* Repair Manual Specific to Your 1989 Chevy G20: Essential for detailed instructions and system specifications.
Again, I strongly advise against attempting this yourself unless you have extensive experience working with automotive AC systems. The risks of injury and environmental damage are significant. The cost of a professional repair is far less than the potential cost of a mistake.
