Hydraulic braking and damping
The guide describes piston hydraulic braking for blank-firing protection and hydraulic damping to absorb shank rebound energy and compensate feed movement. Consult the manufacturer's documentation for the functions and operating conditions of the exact model.
These features help explain the design; they do not establish the condition of an individual machine or replace an inspection.
Rotation binding
The guide describes a rotation inlet sequence valve sticking after contamination by hydraulic-oil impurities, and illustrates damaged rotation sleeves and drive gears. It identifies inadequate lubrication and long-term fatigue wear as associated factors.
Record the direction of binding, operating conditions, lubrication status and photographs for a technician to inspect the oil circuit and components.
Weak or absent percussion
One guide example links weak percussion, a fluctuating pressure gauge and shaking hoses to inadequate accumulator nitrogen pressure or a damaged diaphragm. Another describes normal rotation without percussion where the impact stop valve was sticking or damaged.
These are possible investigation clues, not a diagnosis for every similar symptom. Qualified personnel should inspect and service the accumulator and hydraulic system using the manufacturer's procedures.
Difficulty collaring at low percussion
The guide illustrates damaged shank rings and worn bronze bushes with excessive clearance, and suggests measuring the bush in such cases. For a parts request, provide the complete model, part number, damage location and photographs, then confirm the match.
Source: GLOBMACH Hydraulic Rock Drill Parts Selection Guide, printed pages 84, 87, 89–90 and 92.