In HC50 Hydraulic Rock Drill (or Hydraulic Drifter) systems, the Lip seal 86322278 is a “dual-defense” sealing component—its flexible lip not only locks in hydraulic fluid (critical for maintaining system pressure) but also blocks dust, rock chips, and moisture from entering internal parts (a top cause of premature drill failure). With over a decade in mining equipment maintenance, I’ve seen generic lip seals fail in as little as 300 hours: they use low-quality rubber that hardens or cracks under HC50’s high pressure (1500+ psi) and temperature fluctuations, leading to oil leaks that waste costly fluid and corrode components like the piston or cylinder.