This A/C "class" will be worth sitting through for both the DIYer and the professional. Here is my A/C playlist    • A/C and Cooling System Diagnosis and ...   :55 where to start with any A/C problem 3:00 visual inspection, what a leak looks like 5:40 type of refrigerant oil in a retrofitted system 8:08 how to tell if your A/C compressor is running 10:33 compressed air vs nitrogen to find a leak 14:00 locating a leak with soap/water 16:26 testing an A/C compressor without a refrigerant charge 18:50 pressure testing (max psi) 26:33 pressure decay test after leak repair 31:50 using a micron gauge for leak testing 35:46 adding oil to an A/C system 40:25 decay test with a micron gauge 48:58 charging an A/C system with 12oz cans 53:50 using hot water to charge an A/C system 55:55 in car temperature testing 58:40 what a low charge looks like on your psi gauges 1:02:22 using a sight glass to indicate charge level 1:05:31 how to remove high pressure from your gauges 1:10:44 final comments on a micron gauge (25400 microns in 1" of vacuum) ScannerDanner Tools: https://www.scannerdanner.com/tools.html https://www.amazon.com/shop/scannerdanner For more information on this topic, I have written a “field manual” called Engine Performance Diagnostics which is available at www.scannerdanner.com as an eBook or paper book. Want even more diagnostic training? Whether you are a DIY trying to fix your own car, someone looking to become an auto technician, or a current auto technician that wants to get more into diagnostics, subscribe to ScannerDanner Premium https://www.scannerdanner.com/join-scannerdanner-premium.html There is a 14 day free trial. On ScannerDanner Premium I will bring you right into my classroom at Rosedale Technical College. You will find page for page lectures taken right from my book as well as exclusive classroom type case studies. What is so special about these classroom case studies? I pull live problem vehicles directly into my classroom and we troubleshoot them in real time, using and applying the theory and testing procedures we learn during the classroom lectures. There is no better on-line training of how to troubleshoot automotive electrical and electronics systems anywhere! Disclaimer: Due to factors beyond the control of ScannerDanner LLC, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. ScannerDanner LLC assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. ScannerDanner LLC recommends safe practices when working with power tools, automotive lifts, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video. Due to factors beyond the control of ScannerDanner LLC, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user and not ScannerDanner LLC.