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

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

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 spanOne 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 ChinaUpdate: Performed 17 auto a/c vacuums since purchase, no complaints ....

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.

As long time ago trained HVAC technician, I keept my 30 years old vacuum pump. When tried to evacuate a minisplit, it only pulled 1,000 microns, even with a new oil. I needed a better pump and decided to buy the Robinair 15310, single stage. I was surprised to get as low as 140 microns. This is amazing vacuum pump. If you need a low vacuum and are tight on the budget, this pump is what you need. Fast, quiet, running cool.

Worked as advertised. Disturbing, annoying noise though. Not just loud, like something wants to come loose and hit you in the head. This reflects a lack of high quality R&D, they design it on paper, mfg and assemble the parts then box em up with no regard to testing or refinement. I guess at this price we should expect no more. It drew vacuum to just over 29in at about 200' elevation. It is not a precision machine.BTW mine was a "used warehouse deal" and certainly was used. Full of old oil and covered with a grimy smelly old rag in its box. On the good side it was not beat up and came with cord, adaptor and manual. However no oil for change and fill so the $13 spent on that was about the same as the discount! I knew it would be used but assumed wrongfully they would replace a missing bottle of initial oil fill.So my advice is skip the open box deals because they are no deal. I doubt this was even inspected as they claim, would they have left a nasty old rag in the box or thought the oil should be golden brown?

I use this pump for one-man brake bleeding and it does a fantastic job. It seems well built and solid, unlike some of the other lower end vac pumps out there, and as such should last a long time with occasional use. If you’re an HVAC tech, you may want to go up a level but for my use I couldn’t be happier.

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.