How to Change Vacuum Pump Oil

Posted by COREVAX on 19th Apr 2021

When do I change my vacuum pump fluid?

  • After a 100 hour break-in period of pump operation.
  • When the pump fluid becomes contaminated or is(and/or) discolored.
  • When condensation in the pump fluid is present.
  • Before and after the pump has been stored for a long period of time.
  • When the vacuum pump level is significantly higher than the rated blankoff vacuum. This is best tested with a high vacuum gauge mounted directly on the inlet port.
  • When the vacuum pump is not reaching the desired vacuum level. This is best tested with a vacuum gauge placed directly on the pump.
  • Depending on your oil type, application and possible contaminants, the frequency of oil changes can range anywhere from daily to yearly. and set a frequency which could be from daily to yearly depending on the oil type, and application.

How to Change Vacuum Pump Oil?

  1. Turn the pump off and drain the fluid from the pump. Allow the fluid to drain into a suitable container.
  2. After the oil flow diminishes, switch ON the pump, and allow it to run for about 10 seconds and then switch if OFF. Tip the pump up to allow for any remaining fluid or particulates to drain out.
  3. If the fluid drained from the pump is discolored, contains particulate,has a foul odor or is very dirty, flush out the pump using the procedure below until the drained fluid is clean. If your pump requires more than two flushes, it may need to be rebuilt with a new repair kit.
    1. Reinstall the fluid-drain plug into the drain port.
    2. Refill the pump with VacOil FF Flushing Fluid until the fluid level is visible in the lower rim of the fluid sight glass.
    3. Blank off or valve off the inlet port.
    4. Turn ON the pump and allow it to run for about 10 minutes.
    5. Turn the pump OFF and refer to step 1 to drain the vacuum fluid.
  1. Charge the pump with the specified fluid as described above to the center of the sight glass or the specified fill line.
  2. Reinstall the fluid-fill cap.
  3. If possible, test and record the blankoff vacuum level of the pump with the new fluid for future reference.