Lots of physics with this stuff! And thanks for the fantastic reply. Yep, I understand that NCG's will overwork the system and compressor, and yep I understand the hazards of moisture in the system, and yep I agree that I'll need a vacuum and proper set of gauges for both high and low sides. When it...

R12 is illegal in Canada. Either use R12a (only compatible refrigerant that I know of with this system) or evacuate system for PAG oil and 134a. PAG and R12 don't mix!

Thanks for the response. Any thoughts on mineral oil? Where do I find R12? A good tip that the system doesn't necessarily hold pressure if it holds vacuum. With that in mind, I'm pretty sure the system isn't loosing refrigerant. Any ideas that would explain intermittent cold? No Auto Zone up here in...

Hello I'm new here! Thanks for having me. My AC system works intermittently (yes I know about the leaky monovalve) and I don't know why. I have a new evaporator/drier and TXV valve sitting in a box. The car came to me without a belt attached to the compressor. So I put one on and recharged the syste...