Disclosed is a torque limiter having driver mandrel and driven axially aligned mandrels, a piston movable into and out of an engaged position wherein the driver and driven mandrels are coupled together to transmit torque there between. Hydraulically locking the movable piston in an engaged position. Disengaging the hydraulic lock when during rotation when a specified torque magnitude is exceeded to allow relative rotation between the mandrels. Resetting the torque limiter by hydraulically locking the piston in the engaging position when relative rotation ceases or is reduced.