Magura Royal Blood Mineral Oil The bleeding of a MAGURA brake is not a routine chore, because the MAGURA Blood hydraulic oil does not absorb water. It in fact lubricates the whole braking system. If ever filling and bleeding is necessary after a fall and repair of the tubing, use only MAGURA Blood hydraulic oil and never DOT brake liquid.Buy Magura Components from Chain Reaction Cycles, the World’s Largest Online Bike Store.