Important Safety Notes:
* Do not attempt to recharge your AC system yourself unless you are properly trained and have the necessary safety equipment. Refrigerant is under high pressure and can cause serious injury if handled improperly. Improperly adding refrigerant can also damage your AC system.
* R-134a is not environmentally friendly and should only be handled by certified technicians. There are also legal ramifications in many areas.
* A proper recharge requires more than just adding refrigerant. It usually involves checking for leaks, evacuating the old refrigerant, and adding the correct amount of oil as well.
It's always best to take your Chevy truck to a qualified mechanic or AC specialist for refrigerant recharge. They have the proper tools, knowledge, and safety equipment to do the job correctly and safely.