How to Charge the A/C on a 1992 Buickby Mark Robinson; Updated November 07, 2017
Items you will need
Recharge service hose and valve with gauge
Keeping your air conditioning system in good shape is important during the summer months, especially if you live in hot climates. When your air conditioning system begins blowing warm air, chances are you need to recharge your system with the proper refrigerant. Performing this task is relatively simple and there are several do-it-yourself kits available to use. If your 1992 Buick originally used R-12 refrigerant, the A/C system’s compressor, charging ports, O-rings and other fittings must be converted to use R-134a refrigerant prior to charging the system.
Park the vehicle on a flat, level surface and turn the engine off. Open the hood and locate the air conditioning plumbing along the passenger side of the engine bay.
Locate the low pressure charging port on the air conditioning line that goes from the accumulator to the compressor. Remove the cap covering the low pressure charging port.
Connect the recharge service hose and valve to the can of refrigerant. Turn the valve on the hose to puncture the top of the can. Slowly turn the valve in the opposite direction to fill the hose with a small amount of refrigerant. This will also expel trapped air from the service hose.
Close the valve and connect the hose to the low pressure charging port. Hold the can upright to prevent fluid inside of the can from entering the A/C system. Use a thermometer attached to the central A/C vent inside the vehicle to measure the A/C system’s cooling performance.
Start the engine and turn the vehicle’s A/C system to the “High” or “Max” setting. Open the valve on the service hose to allow refrigerant vapor to flow out of the can and into the A/C system. Depending on the size of the can, it may take up to 10 minutes to add the vapor inside the can into the A/C system.
Monitor the gauge on the service hose to prevent overcharging. If the reading on the low pressure charging port is between 25 to 40 psi with the A/C compressor on, the system is fully charged.
Close the valve on the can and disconnect the service hose from the low pressure charging port. If you need to add another can of refrigerant, remove the recharge service hose from the empty can and attach the hose to the new can of refrigerant. Repeat the procedure above for adding the additional can of refrigerant to the A/C system.
Do not overcharge the A/C system. Doing so can cause damage to the A/C compressor and other components of the system.