The air must be bled from the Electronic Limited Slip Differential whenever a component is separated or a performance issue occurs. A scan tool operates the ELSD pump motor, but the air bleed must be verified, and the hose connections will not allow fluid to pass unless connected to a mating fitting. GM-51381 allows the pressure hose from the pump to the RDM to pass fluid into an approved container, while the ELSD pump operates to purge air from the system. GM-51381 attaches to the RDM end of the pressure hose, and the pump is run per the published bleeding procedure to verify fluid flow and air purge