Hi,
recently I made a piece in prepreg under vaccum in an oven over the night (8h) and in the morning there were a lot of oil evaporation (like a fog) in the room and the oil level of the pomp was very low and around the pomp  was oil as it as was coming out of the chimney. Also the pomp made a louder noise then usually.
But I did check the oil level before using the pomp. 
Could you tell me where this problem is coming from?
Thanks in advance
Christophe