recently got a EC.4 vacuum pump and the first time I used it, the oil changes coller to a milky white after running for 5-10 min against a closed Catch-Pot to check everything was properly sealed and heald a vacuum . and I just changed the oil as I thought it was just moister build op it the vacum pump from storage. but after using it for a 4 infusion I notice the oil had chang coller again to a dark brown so I empty the pump oil, and noticed som small metal parts in the oil, and was curious if there is a problem with the pump ore it is just leftover from manufacturing that wasn't cleaned properly