Kozyvacu Dual-Stage Rotary Vane Vacuum Pump for HVAC/Auto AC Refrigerant Recharging, EPoxy Resin or Wine Degassing, Laboratory, Medical or Milking (500P)

This vacuum pump is well built and heavier than I expected. Exceptional quality build. I used it to vacuum my auto AC and it went to about 27 mg in less than 2 minutes. If left for a half and hour it goes down to about 29.5 mg, provided you don't have any air leaks. Its very sturdy and performs exceptionally well. Less noisy than I expected.

Re Kozyvacu 5CFM 2-Stage Rotary Vane Vacuum PumpI've used this pump a few times to pull a vacuum for cars A/C. I found it to be efficient and surprisingly quiet. It pulled the maximum vacuum within a matter of minutes. I have left it on for about 1/2 hr with no problems (it obviously got a little hot as expected).Build quality seems fine. Other folks have mentioned the oil mist from the exhaust. I can't comment on if this is normal for vacuum pumps but knowing it may do this I connected a length of pipe to direct the exhaust. This issue wasn't a problem to me.(Note, I chose the 2-stage, 5 cfm model)

I bought this vacuum pump to stabilize wood turning blanks and degas wine. The pump arrived before my vacuum pot, so I decided to setup it up for degassing wine. My one and only criticism of the unit is the two fitting for attaching a vacuum line. They are a 1/4" Flare and 1/2" Acme. If you're a refrigeration guy, these are perfect, but if you're a woodworking wino, they can be problematic. I wanted to end up with a 3/8" nipple fitting for a hose. After a couple a trips to hardware stores and purchasing the wrong fittings, I became frustrated and removed the fitting from the pump, took it to the store, handing it to the clerk and told him what I wanted. After much digging around, the clerk came up with a variety of fittings that when combined would accomplish my goal.One thing I noticed when I removed the fitting from the pump, was the thread sealant. Instead of typical semi soft pipe putty, the sealant was hard like glue. When I reinstalled the pump's fitting, I used Teflon tape. I assembled my degassing rig and fired it up. The vacuum gauge read a maximum vacuum of about 25 Hg. Fine for wine but not ideal for stabilizing wood.The next day my vacuum pot arrived. It came with all the fittings and vacuum gauge installed. All that needed to be done was to attach the vacuum line directly to the 1/4" flare fitting on the pump. No adapter needed. I fired up the vacuum pot (after changing the pump oil) and watched as it maxed out at about 27 Hg of vacuum. Acceptable but not great. Out of curiosity, I put a few drops of oil around the pump's fitting were it screws into the pump body. Within a few minutes, the oil had disappeared. Before doing the next batch of wood, I removed the fitting, cleaned the threads with a pick and wire brush, and reinstalled the fitting using 5 minute epoxy as thread sealant. The next time I ran the pump, it pulled a 29+ Hg vacuum that eventually got past 29.5 Hg. At my elevation of 825' above sea level, that's about as good of a vacuum as you can get.I am on my 5th batch of wood and have not changed the oil in the pump. It's still pulling a near perfect vacuum. Speaking of oil, when the pump is running, an oil mist is emitted from the exhaust port. I would avoid breathing it. Rather than wear a filter mask I simply put the pump outside. The good news is, when the pump reaches maximum vacuum (and there are no significant vacuum leaks) the mist diminishes almost completely. I still run the pump outside. In cold weather, I keep the vacuum pot inside and run the power cord and vacuum line under the garage door to the pump outside. The cold air helps keep the pump cool during operation. In 50+ degree temps, the pump gets pretty warm after running for a couple hours or more...not burning hot, but uncomfortably warm (which is normal).Overall, I'm very pleased with this pump, especially at this price.

The vacuum pump did a great job on my 1969 Pontiac Lemans A/C , pulled a vacuum down to 29 inches of mercury and held vacuum. Great pump. Highly recommend for the price cannot go wrong

Pump works well. The only problem that if you let it pump at 3.5 cfm it will fog lots of oil out. I had to limit air flow before system was vacumed a bit and after that fully openened valve, that way it did not fog.