Orion Motor Tech Vacuum Pump, 3.5 cfm 1/4 hp HVAC Single Stage Vacuum Pump for R12 R22 R134a R410a R502, Auto AC Vacuum Pump Kit for Automotive Air Conditioner Resin Degassing & More, Oil Included

Unit works as it should. Essential if you are doing AC stuff by your own. Great vacuum pump. Hope it lasts.

I opened the box, added the oil that came with this OMT vacuum pump, connected a CPS vacuum gauge also recently bought from Amazon, directly to the vacuum pump, and started the vacuum pump to test its ability to pull a vacuum. After several minutes, I reached the astonishing low vacuum of 18 Microns! This is keeper!

Performed perfectly. I purchased this for installing 2 split Ac units to put in my home to replace a central a/c unit that was failing. I needed this to vacuum the lines out as the lines on my units that were not pre-charged. It worked for me the first time on both units so not having to pay a technician to install the units saved me a ton of money. I believed I let it run about 25 or 30 minutes but that may have not been necessary. I just hooked it up and walked away for a while. It pays for itself after 1 use. I do about 90 percent of my projects without acontractor so I have to occasioally purchase specialty tools and this worked great.

A vacuum pump is a mandatory tool if the AC system is fully discharged. After fixing the leak, simply run this pump for 30-45 minutes to remove all moisture from the system. Then charge with Freon.I've used it on R134A automobile systems and it works well. I have not tried it on a home HVAC yet. I expect it would be a good pick for a mini-split installation or repair.

Rey happy with purchase

I use this for transmission vacuum testing like valve bodies and pump valve train. So far I’ve ran this for 30-45 min settings and have had no issues. Fairly small pump in physical size so it doesn’t take up any space and is very quiet compared to others I’ve used.

I purchased the **Orion Motor Tech 3.5 CFM 1/4 HP Single Stage Vacuum Pump** expecting a reliable tool for my HVAC and auto AC needs, but this thing is an absolute **disaster**. From the moment I unboxed it, I could tell the build quality was subpar.### **Major Issues: **1. **Cheap Materials & Poor Build** – The housing feels like flimsy aluminum, and the components seem poorly assembled. Within minutes of running, the unit started vibrating excessively and making a loud rattling noise. The handle even felt loose.2. **Oil Leaks Everywhere** – After filling the pump with the included oil, I noticed **a major leak** around the sight glass and base. The seals seem non-existent, causing oil to drip constantly. I had to wipe the mess repeatedly, and after only a few uses, the oil was already contaminated.3. **Extremely Weak Suction** – This pump claims to be 3.5 CFM, but in reality, **it barely pulls a vacuum**. I tested it on an AC system, and after 30 minutes, it failed to reach the proper vacuum level. Compared to other pumps I’ve used, this one **underperforms drastically**.4. **Overheats Quickly** – After just 10 minutes of operation, the unit became **too hot to touch**. The cooling system is clearly inadequate, and I’m worried about long-term durability.5. **Unreliable & Short Lifespan** – After a **few uses, it completely stopped working**. The motor struggled to turn on, and eventually, it wouldn't start at all. Contacting support was a nightmare—**they ignored my emails** and offered no real solution.### **Final Verdict: **This is a **waste of money** and a **frustrating experience**. If you need a vacuum pump for serious work, **DO NOT buy this one**. Spend a little more on a trusted brand —you’ll save yourself time, frustration, and money in the long run.⭐ **Rating: 1/5 – Absolute Garbage. **

Great pump for the money, quiet and simple to set up.