Review on 🔧 Efficient AUTOGEN Single-Stage 4.5CFM Vacuum Pump: Ideal for HVAC/AUTO AC Refrigerant Recharging, Wine Degassing, and Milking Cow - 1/3HP 5Pa 110V Air Vacuum Pump for R12 R22 R134a R410a by Mardrequs Dorsey

PROS: + Dual outlet + Large oil sight glass + Quiet + Built in thermal protection CONS: - Required oil not included, single stage level pump. Once I had the right amount of vacuum oil and followed the instructions for adding and breaking in oil, I was able to quickly pull the vacuum on the A/C in my 4Runner. I've attached a video to demonstrate how fast it works. It was very quiet compared to any other vacuum pump I've used in the past, which is a nice feature as you really should leave it on for 30-60 minutes to allow the system to evacuate well and any moisture left in it to evaporate is. It got warm after an hour of operation, but not hot enough to hit the thermal cutoff limit. The day I shot the video it was about 85 degrees Fahrenheit. Water boils at 86F at 28.67 inches of vacuum, so the goal is to go a little above, like at least 29 inches for a while to drive out the moisture in the system. I help the process by heating system components like the dryer with a heat gun to make sure every last drop of water is boiled away. I think the only negative comment I can make is the lack of vacuum oil. There are many similar or comparable units on Revain that include the required oil as part of the price. If you have to buy extra oil, that adds about $14 to the price, and you end up with a lot of extra oil that you probably never need unless you use this pump every day. I have to deduct a star for the lack of oil. My final comment, the description says this pump can also be used for "wine degassing, cow milking". I will read about it.