Robinair 15500 VacuMaster Economy Vacuum Pump for Air Conditioning and Refrigeration Service; 2-Stage Pump, 5 CFM Free Air Displacement, 1/3HP 115V/60HZ Motor, 35 Micron Rating

Awesome tool, does a great job. Always wanted one of these.

I have read some of the reviews of how the pump is used and the oil turns black or spit out oil i can say i did experience the oil turning a little dark but ive bought the pump with new Robinair Oil and followed the instructions, ive also let it ran 10 more minuets after the initial brake in period just to make sure everything worked well. ive changed the oil after and let it ran again to see if it was just old oil that came with the pump or if the pump was actually burning or was defective. i am happy to say that it was just the oil that came in the box. ive used it for 2 hours on a job and checked back and the oil is still some what clear but is understandable seeing how the AC system had a lot of moisture so the oil would look a little cloudy, changed it and started on another job and again no problems had a strong vac micron levels were where it should be. the oil that "leaded out" was dude to a very slight over fill of oil after ive adjusted the level no issues at all. my advice is to fill the pump up to the point were the edge of the oil surface tension reaches the sight glass line doing so in my case seems to fix the spitting oil out the exhaust filter, if you cant get it just right i dont see any reason to make a small extension to compensate the oil spitting out the exhaust filter, over all if your a DIY or dont know how to use a vacuum pump or service it ask some one for help because this pump works very well for small to mid side jobs. the only thing i want this pump to have was a larger oil capacity for a longer run time so i dont have to stop it and change the oil as often dude to the high humidity area where i had used this pump in. for the price you pay for it your getting a pretty good deal, most likely buy the 8 cfm in the near future just to save some time hope this helps someone.

Very high quality pump. I've owned others and not only could I tell an immediate difference in build quality by how heavy and well put together this pump is compared to the others but the quietness and deep vacuum ability are unparalleled. I live in the NE heights of Albuquerque so my elevation is around 5400ft (1645 meters) above sea level. Most people forget to calculate elevation into the amount of mercury your able to pull but I'm here to tell you it factors a GREAT DEAL INTO IT. For instance at my elevation I'm only supposed to be able to pull 25inHg with a vacuum pump that pulls 29-30inHg at sea level (San Diego, CA for instance). So if your at a high elevation like me(Denver for instance) and can't understand why your vacuum pump rated for 29inHg is only pulling 25, it's not the pumps fault (more then likely). Bc the higher your elevation the lower the available atmospheric pressure. Why the meteorology lesson you say?! I'll get to the point. Even tho this pump is technically only able to produce 25inHg at 5400ft it was consistently producing beyond that teetering between 27-28inHg which along with the build quality and quietness of the pump should make you not even consider the cheaper pumps (which I wasn't able to get more then 25inHg from) and spend the little extra money on this. I've had for about a month and a half at this point and used it to pull vacuum on 3 different vehicles (one of which I've pulled a few times bc of how old and long it was open to the elements) and the oil is still really clean. I did just get my replacement robinair oil tho- 2 quarts~$20 on Amazon so I'll be replacing it before the next run-also bc it is a tad low. I'll update review as it gets older if I have any issues but based on build quality and the maintenance I'll give it- I don't suspect I'll have any. Sorry for the winded review! Hopefully it helps someone!

My old Robinair 15000 is about 40lbs heavy and it walks a lot during pumping which I hate. This 15500 is so light and running smooth and zero walk. I would give it 5 stars if the Operating Manual is not this bad. The manual shows all the external service parts but it never explain the function of the Exhaust Fitting. Some users even think it is for oil filling plug. Then the section it instructs how to shut off the pump correctly, involving 3 or more steps, except that it never says when to turn the power switch off. Many users had complained about the bad Operating Manual. I suggest that the company should demote those people responsible for the Manual. Edited: after using it on 3 mini split systems installation, I can confirm that the pump is doing great job: no oil consumption; it pulled down to 80 microns less than 15 minutes on a tight connection using copper pipe instead of rubber hose even I only changed oil once during 1 month working on 3 units installation. It just has a very bad unclear User Manual.

My 15500 arrived beat to death in shipping, but despite that, it sure worked well. I was careful to follow the oil fill directions in the manual, and had no problems. I attached a micron gauge to the vacuum port, and it pulled down to 7 microns. Outstanding. Pros on Youtube will show you all manner of elaborate hookups, and they need those when speed is important, but since I was just evacuating a 3/4" line set and evaporator coil for a new heat pump install, I decide to try a simple hookup. The pump connected to the service hose on my manifold gauge set (standard 1/4" hoses). The low-side hose connected to the suction service valve through the straight-thru port on a Yellow Jacket core tool (core was removed from the service valve. The high-side hose connected to the liquid line service valve through a T fitting that came with the CPS micron gauge. I left the schrader valve core in place on the liquid side. The micron gauge went on the T fitting side port, through a Yellow Jacket ball valve so I could isolate the gauge. First pass, this little pump pulled it down to 200 microns within 45 minutes. I stopped it and isolated the pump using the valves on the manifold gauge. As expected, the reading rose, stabilizing around 980 microns. It held below 1000 microns for three hours. Second pass, it pumped down to 150 microns; I did not time it, but it was between 30 minutes and an hour that I left it alone - that's plenty fast enough for my purposes. Pump isolated, it stabilized around 350 microns, well within the heat pump manufacturer's guidelines. Job done. I found it to be fairly quiet too. I think this pump has plenty of capacity and it performs very well. Pros who need a pump for the most demanding daily use might want something else, but this Robinair is fine for the rest of us.

There is nothing to hate about this pump! After reviewing multiple different pumps, I settled on this one knowing that I wanted a 2-stage pump. This held a vacuum for well over 90 minutes and is super quiet. The pump never got too hot to the touch and just simply worked. This was used to vacuum 3 line sets totaling just under 125 feet. For those wanting to install a mini-split yourself - this pump is a perfect addition to the Yellow Jacket R410A manifold setup, 3/8" MegaFlow Vacuum Hose, and both the Appion MGAVCT (1/4") and MGAVCR (5/16") valve core removal tools. If you decide to do this yourself - rent, lease, or buy a nitrogen bottle from your local AirGas or equivalent so you can purge the lines, run a pressure test, then pull a vacuum. Pulling a vacuum alone is not enough to ensure your lines are leak-free. I am not an HVAC tech - just a motivated home-owner - that was motivated to finish this myself after getting a quote of over $7K to pressure test and vacuum the work I already completed, and install a concealed-duct unit in the attic. I saved myself about $6K! Sure, manufacturers want you to have a licensed HVAC tech to do the work (or release the refrigerant) for warranty purposes - however, when properly tested and vacuumed prior to releasing the refrigerant, these units will last as long as the typical central AC systems.

I committed the typical amateurish error of trying out cheaper two-stage vacuum pumps...with predictable results. They either didn't perform as advertised right out of the box, or they failed within several uses - even with proper maintenance. This thing, however, delivers on the promise. I filled it with the included oil. First time powering it up, it pulled the rated vacuum quickly when dead-headed. That first charge of oil became cloudy after just a few uses, so I drained it and replaced it with fresh Robinair vacuum oil. At that point, the ultimate vacuum plunged to 9 microns. (I suspect that the first charge of oil took the brunt of the break-in, and that's why it clouded up so quickly. But that's something to be aware of if you buy this pump. Keep a close eye on the clarity of the first oil charge, as it will probably cloud up pretty quickly.) Since then, this pump has been worked very hard. It has been operated for hours on end with no loss of performance whatsoever. Since my application doesn't expose the oil to excessive moisture, the oil has remained clear after the equivalent of days of operation. There is oil fog released when the pump is operated under no load, or when it is under load but evacuating at a high flow rate. It's inevitable and is present with all pumps of this type. There are aftermarket oil mist separators available that can mitigate the oil mist, but they're expensive. Just expect the oil mist, and make sure you have adequate ventilation wherever the pump is operating.

I originally purchased the lower model version, the 15300 3 CFM, and I wasn't really pleased with it and then I come to find that this one the upgraded version is actually a few bucks cheaper..... what? The same pump design but more power for cheaper? Yes. and it works a heck of a lot better too. Will bring any gauge to below -30 Hg within 10-20 seconds. All this being said it is amazing for Vacuum purging BHO. With the older lower model pump it could take anywhere from 5-7 hours to get some oil under 110F to not move, but with this new one I swear I can get it done in 2 hours. This thing is quiet and a beast. Make sure you read the directions properly when adding oil. You don't just add oil until it reaches the oil fill line. You must turn the pump on, take off the exhaust fitting, and close one of the caps, and leave it running for one minute. After that one minute the oil level should be where the oil is actually at. So you need to run it for a minute to check oil levels, but other than that this thing can run for a long time and will get hot. Not a problem though cause this thing was designed with heatsync technology and stays cool everywhere else except for a few places. All in all I loved this thing way better than the lower model and it was CHEAPER. Get this thing if you need a pump to pull -30Hg and beyond.

es una gran bomba de vacio para moldes de silicona y resina. la regrese debido a que un tapon estaba atorado, aun asi estoy en espera de volver a comprarla. si es tu primera bomba aqui te dejo unos tips. -el vacio maximo depende de tu altitud, averigua el vacio maximo en el lugar en el que vives. -si de gasificas silicona de alta densidad es importante que sepas que nunca dejara de sacar burbujas, la silicona estará lista cuando regrese a su volumen original (o cercano) después de haber inflado. -en un tanque de 4.5-5 galones me toma aproximadamente 15 o 20 min en de gasificar por completo debido a mi altitud. usa resina y silicona con "pot life" más larga que eso. (con líquidos menos densos la velocidad es mucho mayor). -por el amor de dios sigue las instrucciones casi todas las reviews bajas son por no seguir las instrucciones.

Second one of these pumps I brought, only because the first one was so good someone wanted to buy it off me. These things are amazing machines, pulls -30hg and more, quite as you could pray for, no smoke, lasts forever, even after the first one was used with no cold trap and pulled tons of isopropyl direct to the pump, still works like a charm. I do not recommend this though it will shorten the lifespan of your pump. Get a cold trap, and it will last for years. I'm talking heavy use too, like 6+ hours a day running no problems.

It's not often I come across a product that exceeds all my expectations but the Robinair 15500 is the exception. This pump is quality workmanship throughout. Yes it's a little more expensive than some vacuum pumps you can find but that difference in price is more than offset by the rugged build quality and performance this workhorse provides. Add to that the after sales service and support that Robinair is famous for and you can rest assured that this will be one purchase you will not regret making. Bottom line? Five star vacuum pump from a five star company.

Excelente bomba de vacío, llevo un par de años con ella y sin ningún problema logró vacíos de 100 micrones en Minisplit de 2 toneladas

I had the smaller single stage Robinair 15310 and it did work quite well. This unit just works that much better. I do woodworking and use this to stabilize wooden blanks for pen turning. Yes it can pull a vacuum quicker, but in my use I don't need the speed and when I start stabizing, I actual leave a bleeder valve open to slow the vacuum down. Where this unit shines is pulling that last bit of air out of the chamber. they say that the single stage can get to 50 microns. I don't know if I really ever got there. this dual stage is rated to 35 microns and I am getting a better pull and pulling far more air out of the wooden blanks than I could with the 15310. Yes it cost double, but worth every penny.