Mercury Sable Forum : “Does my 1999 sable have freon in the airconditioning system”

Should have r-134a or suitable substitute.

Now the better question why?
If you've had a leak you need it fixed first and the system needs to be evacuated prior to charge for proper system operation.  those little cans at wal-mart are kind of a joke really... at best a band-aid for a problem.

And never attempts A/C repairs yourself take it to a shop.
1) It's dangerous
2) In most cases it's illegal. (EPA regulations as a result of Clean Air Act, and other acts of legislation)