A Guide to Changing the Oil in Your Vacuum Pump

A common question for vacuum pump owners is, “How often should you change the oil on a vacuum pump?”  It is an excellent question and reminds us that periodic maintenance keeps your equipment operating at optimal performance and extends the life of your pump.

We recommend every 500 hours.  However, there are certain circumstances in which this timeframe may vary.  We encourage you to the check the following issues:

  • If the oil is observed in the sight glass to be contaminated.
  • If the oil turns brown and foams or any discoloration is noticed.
  • If there is condensation present in the pump fluid.
  • If the pump has been unused or stored for a long period of time.

These are not the only circumstances that warrant changing the oil but a few to be aware of.  Ultimately, knowing your applications, pump environment and usage will assist you in determining your frequency.

Our Rotary vane vacuum pumps normally utilize BV68 or BV100 oil.

How to Change Vacuum Pump Oil?

  1. Make sure the pump is at operating temperature before changing the oil, ideally after running for at least 30 minutes. This will maximize your oil drainage.
  2. Turn the pump off and remove the oil drain plug. Keep in mind the oil will be hot!  Keep your hands clear of hot oil!
  3. Drain the fluid from the pump.  Allow the fluid to drain into a suitable container. While tilting the pump will improve drainage, some oil will remain in the pumping chamber.
  4. If the pump has an external oil filter, replace it by using an oil filter wrench. Lubricate the rubber seal with a small amount of the new oil and install the new oil filter.  DO NOT OVERTIGHTEN!
  5. After draining the oil, refit and tighten the oil drain plug.
  6. Re-fill the pump with the specified grade of oil as recommended in your Owners Manual, above up to the center of the sight glass or the specified fill line.
  7. Add oil slowly, with the pump in a level position.
  8. DO NOT OVERFILL (up to mid-range on the oil sight glass)
  9. Reinstall the oil filler plug and tighten it.
  10. Turn on the pump and check that the oil level remains below the top of the sight glass.
  11. Check drain plug and oil filter for leaks. Run the pump for about 15 minutes. Check the oil level after 2 hours and add oil if needed.

Another factor to be considered during your oil change, there is a very fine filter inside the vacuum pump.    This filter is called the exhaust oil mist filter or oil mist separator.  This filter is helpful to stop oil smoke from being discharged from the pump.

If you have any questions or need parts and materials to complete your oil change please contact our Service Department at 469-456-4634 and ask for our Pump Specialist, Juan!  You can also find information on our YouTube Channel, https://youtu.be/f8zdHKenTEk