Oil Pump

Drain off 1-2 tbsp of oil Beginning of every batch See pg27, "How do I extend the life of my vacuum pump oil?"
Change oil Approx. 5-6 batches* See pg23, "Vacuum PumpMaintenance, Oil Change"
Power flush Approx. 10-12 batches* See pg24, "Vacuum PumpMaintenance, Power Flush" https://youtu.be/ILVBXqg9oc8
Remove pump cover assembly Approx. 30-36 batches* https://youtu.be/bOGTh9n3NpA

*The number of batches is contingent on the food you freeze dry, the thickness, length of batches, etc.