[Corts60]

As a refrigeration tech, I'm surprised at some of the responses I've heard on here. A few of them completely illegal and dangerous.

R12 is and will always be a better refrigerant than R134a. It is more efficient and it's boiling point is higher than R134a. However, it was discontinued because it is a CFC refrigerant, which is much worse for the environment when released into the atmosphere than R134a, which is an HFC. That is the short version of what I wanted to say.

Now, never ever mix two different types of refrigerants together. I don't care what anybody says on here. If you want to do your truck and your wallet right, just find the leak, repair it, and then convert to 134a properly.