Replacing R12 AC system that doesn't blow cold air, empty before removing?

[grantmiller1]

Thanks, this is the perfect easy way to check!

There was no hiss, so no R12 in the system!

Thanks!...

[grantmiller1]

My car currently has the original R12 AC system. It does not blow cold air. I have a complete R134a system to install in the car, but I was thinking that I should get the R12 refrigerant properly removed...