Oil Guide 600

How do you know when it is time to change your vacuum pump oil

February 12, 2021


When functioning correctly, vacuum pumps can greatly enhance the consistency and efficiency of manufacturing machinery. To do so, however, these pumps must be regularly maintained. Part of that maintenance includes changing the oil. 

Why you should change the oil

Oil-sealed vacuum pumps in the industry utilize the oil to move air, liquid, and process by-products. The oil is critical to optimum performance. However, changing the oil on these pumps temporarily takes the system out of commission, causing lags in production time. It can be tempting to skimp on regular oil changes or skip them entirely, but that will cause the machine to fail earlier than normal and even worse, cause process variability in your process. When your oil has degraded, it can impact the vacuum levels, causing lost production and ultimately lost profits.

When to change the oil

The first resource to consult when deciding to change the oil in your vacuum pump is the manual. When you buy a vacuum pump, it should come with a manual that details maintenance schedules, including oil changes. Keep in mind that oil changes may be needed sooner than the recommended intervals due to the type of application.

Oil color

A good indicator of when to change your mineral or silicone oil is the oil’s color. In general, it should be light, but there is a range of acceptable shades at which your machine will function. If you’re checking the oil in your vacuum pump and it is at shade number 4 or darker, it is time to drain and replace the oil.



Oil should be viscous and mostly clear. If you are checking the oil in your vacuum pump and it appears frothy or milky, it could indicate that there is a leak in the system or that condensation has mixed in with the oil. In this instance, you should not only drain and change the oil, but you should also check your system for leaks. 


If you’ve been storing your pump for 3 to 6 months, it is a good idea to change the oil before running the machine again. Sitting for long periods can cause oil to deteriorate, making the pump function less effectively. Labeling all of your pumps when you put them in storage can help you identify which ones need an oil change.

Preventive maintenance

To extend the life of your vacuum pumps, conduct oil changes as part of your routine maintenance. Rather than waiting until the oil looks dark or cloudy, changing it at regular intervals, as recommended in the manual, can keep the machine running at top performance for a longer period of time and alleviate unexpected equipment failures. 

Changing the oil in your vacuum pumps is a necessary part of keeping your systems running correctly and enhancing your productivity. If you are not sure when to perform this maintenance, check the owner’s manual and the appearance of the oil in your machine, or reach out to the OEM for recommendations. 

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