Accumulator end cover and flushing head
The guide associates cracks in the accumulator end cover with factors including insufficient nitrogen pressure, a leaking charging valve and excessive cover tightening torque. For flushing-head breakage, it lists percussion without feed, corrosive flushing fluid and displacement associated with front-end corrosion among possible factors.
Record the operating conditions, locations of leaks or corrosion, and photographs. Follow the manufacturer's requirements for pressure checks and assembly of the specific machine.
Impact piston and guide surfaces
The guide relates wear or binding in the piston's guide area to possible factors including contamination in hydraulic oil, uneven bolt loading and corrosion of mating surfaces. It also identifies low feed pressure and abnormal accumulator parameters as factors associated with piston cavitation.
Inspect the guide sleeve, mating surfaces, oil condition and operating circumstances alongside the piston; replacing one component alone does not establish that the underlying fault is resolved.
Rotation bearing wear
The guide notes that bearing preload that is too low or too high can contribute to early failure. Preload must be checked against the equipment requirements during assembly; use the manufacturer's values and procedure for the exact model.
Keep evidence for parts matching
Keep photographs of the damaged area and adjacent parts, the rock drill nameplate, full version, part numbers and operating conditions. Check each number and physical part in the directory; a cause described in a case cannot be assumed for another machine.
Source: GLOBMACH Hydraulic Rock Drill Parts Selection Guide, printed pages 102–106 and 109.