Robinair (15310) VacuMaster Single Stage Vacuum Pump - Single-Stage, 3 CFM Silver

Nice, Brand name, Light duty pump. Used it 3 times already and found it to be more than adequate. Easily pulls the rated vacuum AS LONG AS YOU HAVE NO LEAKS. Follow proper repair and charging procedures to avoid poor results and shortening the pumps life. Due to the design of the a/c charge hose fittings, it's easy to have leaks that are hard to detect, which will make the pump look weak. Aside from a defective unit, this is probably the issue with a lot of the "won't pull the rated vacuum" reviews on here. Even though Robinair is a BIG name in the industry, I think this unit is priced fair for something made overseas for occasional use. I'm a Certified Master Technician and Instructor with 35 yrs experience and I researched and purchased this unit for home use. I use the more expensive Robinair equipment at work because they are more reliable in a shop environment. Quality control on products made outside the U S is always a problem, but so far so good. BTW, these units do get hot, make some strange noises at times and can give off a mist and smell. Perfectly normal, just means it's working correctly.

This model cost a little more than most but it works great in my vacuum chamber that I set up for stabilizing wood. So far I have used it three times for 12+hour long sessions with no problems. A little noisy but that is expected. Great machine up until now I was renting the free loaner from Oreillys that I considered just purchasing it since I already had it in hand but glad I didn't. The Robinair pulled more suction and just seemed better built.

Surprisingly, this pump performs above my expectations for its specs and price tag. The unit comes with a 1/4" fitting already installed for the older R12 1/4" gauges instead of a dual port fitting (both 1/4 & 1/2) as shown in image. I have a set of CPS MA1234 guages that has a 1/4 " female fitting on the yellow hose and they hooked up to the pumps fitting w/o using the supplied r134a 1/2" straight adapter. The r134a adapter should be in the box.. Easy oil fill, dosen't matter if you fill through the oil fill or exhaust port. Requires a 10-30 second break in period prior to first use... Anytime you remove the oil fill cap, always inspect the o-ring as mine fell off the cap and luckily I happened to notice. Also, double check drain plug prior to first oil filling out of box as mine seeped a little oil, don't over tighten, just snug as you may potentially damage o-ring... The pump comes with a hex drain bolt unlike a knurled bolt shown in image... Pump will pull a vacuum within 20 -30 minutes on a/c auto systems. After 30 minutes of operation, the unit is safe to touch ( lukewarm ). I was initially concerned with the plastic handle but it has a solid, sturdy feel. The pump will occasionally mist oil out the exhaust port, more so at vacuum start up or if overfilled. As for oil usage, I performed 5 30 minute vacuums w/o any noticeable oil loss. As for loudness, it relatively quiet and safe for indoor use, minus occasional oil mist... I've only pulled a vacuum on five auto 134a a/c systems since purchasing, 3 of these jobs were compressor burnout replacements while the other 2 were refrigerant loss / leak repairs and the oil has just now shown signs of needing to be replaced. I know every manufacturer recommends you change the oil after every use, they also recommend you use only thier brand oil. As I was saying, during the 5th vacuum I pulled I noted the oil was getting milky during vacuum operation upon visual inspection through the sight glass, although the oil was clear after shutdown. Time to change the oil as that is where all the moisture remains that doesn't get boiled off during vacuum, while the frequency of oil change intervals is debatable.... the oil will need to be changed when showing signs of cloudiness in color, poor performance or you can routinely change after every use as recommended should that be the maintenance interval you prefer, no doubt the pump will pull a quicker vacuum with fresh oil.. The pump comes with a bottle of oil that is enough for 1 1/2 fill ups.... Hint: Buy a pump oil that contains no additives, as additives breakdown and contaminate quicker when mixed with moisture. Also, ensure that you install the dust cap on the pumps fitting while not in use to keep moisture out as failure to do so will shorten the oil life span One thing I've noticed is this pump pulls a vacuum pretty quick for its size, you can hear the change in the pump when the pump has pulled most of hte moisture out of the system. On the 3 a/c systems where I replaced the receiver driers and compressors, the pump pulled a vacuum down to 29 µm and 28 µm on the systems w/o drier / compressor replacement. See pics below of vacuum in progress, oil fill port, sight glass and drain plug..... I would have loved to have bought a higher end pump but funds were tight. None the less, I am very satisfied with my purchase, very smooth transaction...The only shortcoming I found.... Made in China Update: Performed 17 auto a/c vacuums since purchase, no complaints ....

Works well. Light weight

Specs are overrated. But it is a solid pump. Not some random quality hit or miss low buck pump. Plus you can get parts for it! Parts! What? In 2025? But again , consider an entry level pump if you want to boil out water in any volume over 1 oz. I put 1/2 an Oz in a vacuum chamber and it took a couple hours to boil it out. it was barely pulling 750. So if you need DEEP vacuum on a large volume, this would take FOREVER! you'd have to put it on an on off cycle timer so it wouldn't overheat. If you need deep space vacuum, get a two stage! If your degassing fluids, this is great I guess. I tried an Oz of alcohol and it burst up and boiled violently on power on !!!. So Never doing that again lol. Great lil starter pump!

Used it on my 1999 suburban when I rebuilt tge AC system. Easy to use and fairly quiet.

Good a/c vacuum pump for the price. Good CFM rating and evacuates system quickly. Portable. The only negative comment it's made in china, hopefully it will stand up to the Robinair name.

Started knockong after like 2 uses. My oil was fresh. Have no idea why it went out so quick. Defective unit? Bought multiple yesrs ago. have it in box still. Kinda disappointed. Would return for a replacement

Excelente marca y muy buena calidad. De lo mejor. Ya llevo unos años con ella y ninguna falla.

To all that have given this brand of pump a bad review, I suggest that you read the manual again. There is a red cap that the manual says to remove to put the oil into. You get a big bottle but it doesn't take the whole bottle to fill the oil tank. You put in enough to get the oil just past the bottom of the view window and then as per the manual, turn the unit on. LET IT RUN A MINUTE. Then when the oil has heated up, add more oil to get it to the fill line. If you put in too much oil, it will give off more mist/smoke, and you may not get as much vacuum. If you didn't read the manual and follow the instructions, you only have yourself to blame. Get a sharpie and put the letter i on your forehead to remind yourself. Hooked it up and put in the correct amount of oil. It gave off a small bit of mist/smoke when starting up but as soon as I started to pull a vacuum that all went away. On my empty 5 gal vacuum chamber it easily pulled 30Hg of vacuum. Then when using it to stabilize some assortment of wood, it pulled all the air out and did a wonderful job. It's not quite as fast at the 2 stage, but at less than 1/2 the price, I am quite happy to wait the little bit more.

Buena herramienta, excelente calidad cumple con su propósito

I needed a vacuum pump for my mini split heat pump installation. I followed the instructions for setup in the manual provided and then vacuumed out my lines on the mini split. The pump brought the pressure down in minutes but I left it on for another five minutes. I had no issues with the oil although the unit did smoke a bit when it was initially making the vacuum. I cannot comment on the durability as I only needed it (so far) for a single use but for the price it was well worth it.

Excelente🙂