Pull Vacuum on Vehicle AC System | 134a Refrigerant 

RU-vidrs please take note of this excellent tutorial. The presenter doesn’t assume anything. Every step is perfectly spelled out Fantastic job!!

Thus is the best video I have found. So educational and super detailed how Does this video only have 89 likes?It should have a million

Yes, very good thorough explanation!

Fantastic tutorial! If the system wont pull past 20, what could be the issue? Faulty pump or gauges or something else?

Thanks for your video. Used this method after replacing ac compressor on my son's 2003 Accord. After using the pump it lost vacuum, albeit very very slowly. Another time it lost a little, then held. In the end I charged it up, and a month later is still blowing ice cold. I suspect the $50 ac vacuum pump/gauge kit I bought from eBay had the leak, or maybe it's hose attachments did not mate well with the Schrader valves. Annoyingly the attachment on the end of the yellow hose on the kit would not fit on ANY of the refrigerant can adapters, visited several Auto discount stores and they confirmed this, so I was forced to spend a further $18 on a hose/adapter set so I could actually add the R134 (any saving on buying a cheap ac kit was lost right there, not to mention the time I spent f**king around). If it stops blowing cold I'll add some UV infused R134 and try and source the leak, have to say the condenser does look a little beat up but time will tell!

Question: why use both ports to vacuum when the system is connected high to low?

Good video on the topic, would have been interested in how much oil you added for the component that was replaced.

How can the gauge recognize pressure if you close it at the gauges?

Geez you see the mitts on sister??!!