16 ► MB256
User Manual
DAILY MAINTENANCE CHECKS
•
Check for loose or missing fasteners. Tighten or
replace as needed.
•
Inspect tool retaining pins and pockets for wear.
•
Check for hydraulic leaks at all fittings and hoses.
Replace any defective hoses.
•
Apply grease to the grease fitting in the lower body
each morning. Grease as needed throughout the
work day.
TOOL STOP AND LOWER BUSHING
Inspect the tool stop and lower bushing for excessive
galling and metal pickup on the tool bit. Also check for
cracks. If cracks are present, the part must be replaced.
The extent of wear of the tool stop and lower bushings
and the tool bit can be checked by moving a NEW tool
bit back and forth and measuring the gap between the
tool bit and the lower bushing. If the gap is more than
.250 in./6 mm, the upper bushing, lower bushing and
tool bit should be replaced. A gap in excess of .250 in./6
mm will cause damage to the piston. Do not just replace
the tool bit or the lower bushing individually as this will
result in premature wear of the replaced component. It is
recommended to replace ALL worn components.
18 inches
Figure 11. Measuring Tool Bit Gap
MAINTENANCE
