How many cans of 134a to use?

The amount of R-134a refrigerant needed depends on the specific system and its requirements. Generally, automotive air conditioning systems may require between 1 to 3 cans (12 oz each) of R-134a, but it's essential to consult the vehicle's service manual for the exact specifications. Overcharging or undercharging can lead to system inefficiency or damage, so using a refrigerant scale or gauge is recommended for precise measurements.