Maybe once a season, or anytime the levers feel a little spongy, we like to bleed our Magura brakes. This removes any air infiltration, introduces fresh fluid, and gets the system back to 100%. Magura's Royal Blood uses mineral oil that doesn't absorb moisture from the atmosphere so the boiling point of the fluid stays consistent throughout its lifespan. Additionally, it is safer for the environment and won't cause harm if you happen to spill it on your trusty steed. Keep Royal Blood on hand if you need to do a quick bleed after shortening brake lines or after disconnecting the hose from the calipers or levers as needed on internally routed frames. Note: Magura brake systems use mineral oil only. Do not introduce DOT fluid into a hydraulic system designed for mineral oil as this will cause corrosion to the internal seals and system failure may result.