In this clip we're going to talk about the proper service procedure to retro fit your vehicle's air conditioning system from R12 to 134A and recharge the system. In this step we're going to talk about the proper service procedure for removing our system and reinstalling another can of refrigerant. 95% of vehicles out there will require more than one can. What you're going to want to do first, is disconnect it from your system by pulling the retaining ring up and wiggling it out. From there it's ok to unscrew it from the system. If you hear a large hissing noise while you're unscrewing it, the gage from the can, that means it's not empty, and you need it to stay on the engine. Continually agitating it for more time. From here what we're going to do is make sure our piercing valve is fully retracted to accidental piercing of another can. Going to grab our can of refrigerant here, shake it up real good. Make sure all the additives are dispersed in the refrigerant, and we're going to screw our gage and charging hose on to the can. Do not screw it down by the gage. That will pierce the can inadvertently, and you may damage yourself. From here what we're going to do is hook this up to the system by pulling the lock ring up and sliding it down with downward force. Just like so. From here we can go ahead and apply the piercing screw. We're going to bottom the screw all the way out. As you can see the gage moved as my compressor engages. It's drawing refrigerant out of this system to the low side. We're going to go ahead and continue agitating it, turning it from twelve to three o'clock. Back and forth. It will take approximately five to fifteen minutes to add your second can. From there what you're going to need to do is do the math to see exactly how much additional refrigerant you're going to have to add. There's a label here which will indicate the amount. Of course the can is labeled with the amount that it has in it. There are sixteen ounces in a pound. Each one of these cans has three quarters of a pound. My system takes one and three quarter pounds, so just a fuzz over three cans is what my system requires. We'll continue agitating it. Like I said it takes five to fifteen minutes to charge the system. This is the proper way to change your can safely and continue your charging process.