Is anyone familiar with the Snap-On ACT 4500?
 

Hello: I need to know if the Snap-On ACT 4500 will work with both R134 and R12. I can't find an online manual for it which addresses that. I saw one of the units online and two tanks are shown inside of it. I don't know if that's one tank for each refrigerant or what. Also, what is a good used one worth?
Thank you.

The pressure/temperature characteristics of 134 and 12 are close enough together that all it takes to convert is tank evacuation, compressor oil change and a fresh oil reciever.

Thanks for your response.
How about the digital readings on the unit? Is there anything that's just calibrated for R12? I imagine in addition to what you stated I'll also need different fittings and related components. I'd like to do work on my a/c system myself without having to go to a shop every time I open it up. Just paying for a shop's labor and $65 per pound freon a couple of times I can purchase the machine, get my 609 and do it myself.

Yes, I forgot, the fittings will of course have to be adapted. Do you want to go from 134 to 12 or 12 to 134?

I'm not sure about any readouts on the system, but I expect that they are simply pressure or temperature readouts.

The machine I converted had no readouts.