An isolated lubrication system for a drill bit is disclosed. The system comprises a body having a cutting arm with a journal and a rotary cutter mounted on the journal. The system also comprises a reservoir in a body to contain a fluid lubricant that isolated from communication outside the body. The system also comprises multiple conduits in communication with the reservoir and with respect to each other. The multiple conduits facilitate lubrication between the journal and the rotary cutter, including the bearings, by means of a gravitational force and/or a centrifugal force acting of the fluid lubricant. Further, the system comprises a sealing system. The sealing system includes a sealing cap provided to the reservoir, a seal provided between the journal and the rotary cutter, and a stepped passageway provided in a clearance between the rotary cutter and a cutting arm of the body.