In HC50 Hydraulic Rock Drill (or Hydraulic Drifter) systems, the Thrust lining 86334109 is a critical “buffer” component for the stopper piston—it directly bears the repeated impact force between the piston and cylinder during drilling (up to 2000+ bpm impact frequency) and minimizes metal-to-metal friction, which is the top cause of premature wear on core drill parts. With over a decade in mining equipment maintenance, I’ve seen generic thrust linings fail consistently: most use low-grade alloy that wears through in 800-1000 hours, leading to increased piston play, reduced impact power, and even irreversible damage to the cylinder bore. These issues force unplanned downtime, costing mines $4,000+ in repairs and lost productivity per incident.