In HC50 Hydraulic Rock Drill (or Hydraulic Drifter) systems, the Lip seal 86307162 is a “critical barrier” for the hydraulic circuit—it uses its flexible lip to form a tight seal between moving components (e.g., piston and cylinder), stopping hydraulic oil leakage (which wastes costly fluid) and preventing dust, rock chips, or moisture from entering the system (a top cause of premature wear on valves and pumps). With over a decade in mining equipment maintenance, I’ve seen generic lip seals fail in just 80-100 hours: their low-quality rubber hardens quickly under the HC50’s high pressure (1500+ psi) and vibration (up to 1800 bpm), leading to leaks that force unplanned downtime—costing mines $2,500+ in repairs and lost productivity per incident.