On pumps and blowers where there are tight seals, a vacuum can occur which will result in the oil being sucked from the constant level oiler. You should install a breather a) in the line between the oiler and the pump or b) on top of the housing of the pump to create an atmospheric condition. NOTE: a closed system oiler will also work.
1/8" NPT breather tubes are threaded into standard fitting provided by equipment manufacturer. We do NOT recommend tapping into OEM equipment.