Robinair 15800 VacuMaster Economy 2-Stage Vacuum Pump - 8 CFM, Chrome Plated for AC Recharging, Refrigerant Recovery & HVAC System Maintenance

I work in commercial HVAC/R and this is the vacuum pump I have been using. READ THE MANUAL. It’s a good pump. I can pull sub 500 microns pretty quickly. Rarely, is it the pumps fault if it does not. Check your welds, hose connections, and such. I’ve had a couple of times where it just was not pulling vacuum quickly. Those times, the issues have been the oil. Which changes quickly and easily. For the price point, you won’t find as reliable a pump. My coworker got the smaller 5 cfm Robinair pump. He likes his. My 8 cfm pulls down much faster. The trade off is my pump is heavy. I typically have to pull it up on rooftops by a rope. The little rubber feet on my unit also fell off in the first few weeks of using the pump. To me, it’s not a big deal. But again, the price is tough to beat. For less than $400, this unit is outperforming units that cost twice that. I use it in conjunction with the Testo wireless vacuum microns gauge. I use these units almost daily. I provided a few photos of the pump on the job. Surprisingly, this pump is not very noisy.I've had this pump for a few months and it works wonderfully. I use it only for degassing silicone rubber prior to making molds. One thing I would strongly recommend is reading the manual carefully prior to use. I believe a lot of the negative reviews on this pump are from people who did exactly the opposite. The pump comes with 2 bottles of oil; I did not need to use both of them. You fill the pump with oil until it reaches the minimum line, then run the pump until it runs smoothly. Then I put the rest of the first bottle in and haven't changed or added more since. This is a strong pump (2-stage 8CFM) so you will get small oil misting but it's nowhere near as bad as the negative reviews say (they probably maxed the oil level before the pump was even turned on for the first time). I use the pump in my garage, and attached a 3-foot 0.5" EPDM rubber gasoline hose to the oil exhaust and directed the tiny bit of fume out the window. I even went outside to check how much mist was coming out and saw intermittent nearly transparent puffs; nowhere near the "heavy mist" that some people are describing. As for vacuum, I get a solid 29 on the gauge of my vacuum chamber, but I also live in PA where the altitude is around 728'. The higher your altitude, the harder it will be to hit 29. All in all, this is a really great pump for the price and does exactly what I need it to do with no issue at all. Glad I ignored the bad reviews and gave it a chance.P.S. What convinced me to ignore the bad reviews was the user manual. It is freely available online (check Robinair's website) and it directly outlined how to avoid all the issues the negative reviews were mentioning. Following the manual personally avoided every issue, which is why I am convinced those negative users did not read it before use. I do recommend buying the EPDM hose, even in a well ventilated area. 3 feet of it cost me < $5 at the local auto parts shop.Have used a half dozen pump brands over the years. Whether made in USA or China, most are garbage. This 2 stage 8 CFM unit works great. It works so well I bought 3 more (deal with parallel multistage compressor systems). My customers have bought them too based on my recommendation, and are happy with product.I did lose a leg shock absorber when pump fell 4 feet from a shelf on the truck. Pump still work fine.Someone complained about pump not starting when turned on. This is a common problem with vacuum pumps, especially when pump oil is cold and happens to me every winter. It is not pumps fault but basic physics. Crack seal where hose connects to pump so pump does not have to start against low pressure and thick oil. Once spinning reseal and pump will work fine. If pump REALLY cold, it is probably not going to start at all. You can heat pump with a propane/Mapp gas torch to heat/thin oil. If this concerns you at all, do not do it.Some have complained about misting. It moves 8 CFM a minute in the beginning. OF COURSE you are going to get mist on any significant system! If you do not want mist, restrict flow until you ger a fair vacuum, but time is money for people who buy an 8 CFM two stage pump. Mist is the tradeoff for pulling a fast vacuum.One last point to make. It is very conmon to not get deep vacuum. Happens all the time. It usually means your system or gauge setup has a leak. It can also be caused by an uncalibrated vacuum gauge, your pump oil being dirty, or you have an improper oil level. All 4 of my pumps still pull a VERY deep vacuum when deadheaded and checked against an accurate gauge.My work had one of these for over a decade and after all that heavy use and no maintenance it crapped out at a most inconvenient time. It was during our Christmas shutdown that I took the pump home to vacuum degas some silicone that I was casting to make some urgently needed parts. Amazon prime to the rescue- I got a replacement pump on Christmas eve with next day shipping and the price was better than I could get from our usual industrial equipment supplier. Pump works perfectly and saved they day when I returned to work with enough finished parts in hand.I have been using this Robinair vacuum pump (15800 VacuMaster) for automotive AC work at home fairly regularly (approx: 25 - 30 times now) since I purchased it through Amazon.ca Feb 2015.- So far this vacuum pump has worked flawlessly for me with no issues at all.- It's reasonably quiet compared to other cheaper lower CFM vacuum pumps I have used in the past.- It does its job quickly and smoothly as it should since it is an 8-CFM two stage pump.- The oil level indicator window is easy to see and judge proper oil level and cleanliness.- The oil drain valve is located in a good position for quick and easy draining as advertised.- It's a sturdy product that is clearly built to last.- At this point it gives me piece of mind knowing it's a quality product and it's ready to go for me anytime I pull it out for use.Not much else I can say about this pump except in my opinion it's a good investment if you are looking for a worry free quality vacuum pump that should keep working for you for years to come as long as you take care of it and change the oil when needed.I hope you found my review helpful.Rick...La compré por la capacidad, pero lamentablemente no cumplió, no hace buen vacío, no llega ni a los 25 pulgadas de mercurio a pesar de dejarla mucho tiempo.no vale la pena gastar tanto, es mejor una sencilla de 1/3generalmente esta marca es muy buena,,,desafurtunadamente me confie y no la puse en marcha antes de un trabajo,, no funciono corractamente, tengo otra igual...y hace el vacio en poco minutos llega a 90 micrones un cilindro de 30 libras y la nueva no pasa de 480 micrones.quise regresarla y se me paso el tiempo de devolucion.