Larry,

You are right to an extent about the downside of duracool.

True, you do have to evacuate and start over if you need to add some, but that doesn't take long to do since I have all the equipment to do it with. It's no big deal, but if you do have a big leak, you have to fix the leak anyway. You would do that no matter if you have r-12 or r-134.

However, I disagree with you on explosion due to a seized compressor. In order to have an explosion, you must have the right mixture of oxygen to propane to make it burn. Another item to consider is when you evacuate the system, there is no oxygen present which is required for an explosion. When the system is charged with duracool, that is all you have, just duracool....no oxygen. If the compressor was to seize, an explosion would not occur because the essential element of oxygen is absent from the equation.

As for contaminating the existing r-12 supplies, I would never do that since I now do my own ac work myself but if I took it to someone, I would evacuate the whole system first. In addition, I have come to the conclusion that r-12 will never be available again..........a losing battle. And even if it was, I refuse to pay the exorbitant prices for this liquid gold. So why even try to use something that is now obsolete. I wish r-12 was available, I would still use it, but we've got to face reality.

Herb
'82 240D
'87 300SDL
'92 300D 2.5 Turbo