Review on Robinair 15300 VacuMaster Economy Vacuum Pump - 2-Stage, 3 CFM: Quality and Affordability Combined by Yung Kaelin

The two units received both had the same issues. The same nut was overtightened at the factory, resulting in housing failures on both assemblies. As you can see from the photos, the hull of the first block was completely destroyed. The second refill had a hairline crack in the same place as the first. Both washers under the nuts were slightly concave from being overtightened. Both devices arrived almost in their original packaging, handling them is not the cause of the failure. I keep this device as it is rarely used as a portable device. But be aware and be vigilant in this matter.